blocks|key|884822|text|谷歌的GSON可以用一种很好的方式做到这一点：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|884823|Gson+gson+=+new+GsonBuilder().setPrettyPrinting().create();
JsonParser+jp+=+new+JsonParser();
JsonElement+je+=+jp.parse(uglyJsonString);
String+prettyJsonString+=+gson.toJson(je);|code-block|syntax|javascript|884824|或者，由于现在建议使用JsonParser中的静态解析方法，您也可以使用下面的方法：|884825|Gson+gson+=+new+GsonBuilder().setPrettyPrinting().create();
JsonElement+je+=+JsonParser.parseString​(uglyJsonString);
String+prettyJsonString+=+gson.toJson(je);|884826|下面是import语句：|884827|import+com.google.gson.*;|884828|下面是Gradle依赖项：|884829|implementation+'com.google.code.gson:gson:2.8.7'|884830|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/google/gson^0|3|4|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@$A|13|B|14|1|15]]|C|$]]|$1|D|3|E|5|F|7|16|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|17|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|18|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|19|8|@]|9|@]|C|$]]|$1|O|3|P|5|F|7|1A|8|@]|9|@]|C|$G|H]]|$1|Q|3|R|5|6|7|1B|8|@]|9|@]|C|$]]|$1|S|3|T|5|F|7|1C|8|@]|9|@]|C|$G|H]]|$1|U|3|-4|5|6|7|1D|8|@]|9|@]|C|$]]]|V|$W|$5|X|Y|Z|C|$10|11]]]]

Google's <a href="https://github.com/google/gson" rel="noreferrer">GSON</a> can do this in a nice way:
<pre><code>Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonParser jp = new JsonParser();
JsonElement je = jp.parse(uglyJsonString);
String prettyJsonString = gson.toJson(je);
</code></pre>
or since it is now recommended to use the static parse method from JsonParser you can also use this instead:
<pre><code>Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonElement je = JsonParser.parseString​(uglyJsonString);
String prettyJsonString = gson.toJson(je);
</code></pre>
Here is the import statement:
<pre><code>import com.google.gson.*;
</code></pre>
Here is the Gradle dependency:
<pre><code>implementation 'com.google.code.gson:gson:2.8.7'
</code></pre>

blocks|key|1099703|text|我使用了org.json内置方法来漂亮地打印数据。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1099704|JSONObject+json+=+new+JSONObject(jsonString);+//+Convert+text+to+object
System.out.println(json.toString(4));+//+Print+it+with+specified+indentation|code-block|syntax|javascript|1099705|JSON中字段的顺序根据定义是随机的。特定的顺序取决于解析器的实现。|1099706|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/douglascrockford/JSON-java^0|4|8|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

I used <a href="https://github.com/douglascrockford/JSON-java" rel="noreferrer">org.json</a> built-in methods to pretty-print the data.

<pre><code>JSONObject json = new JSONObject(jsonString); // Convert text to object
System.out.println(json.toString(4)); // Print it with specified indentation
</code></pre>

The order of fields in JSON is random per definition. A specific order is subject to parser implementation.

blocks|key|885384|text|与杰克逊(com.fasterxml.jackson.databind)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|885385|ObjectMapper+mapper+=+new+ObjectMapper();
System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonObject))|code-block|syntax|javascript|885386|来自：How+to+enable+pretty+print+JSON+output+(Jackson)|885387|我知道这已经在答案中了，但我想在这里单独编写它，因为很有可能，您已经将Jackson作为依赖项，所以您需要的只是额外的一行代码|885388|entityMap|0|LINK|mutability|MUTABLE|url|https://www.mkyong.com/java/how-to-enable-pretty-print-json-output-jackson/^0|5|U|0|0|3|1C|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|D|@$9|11|A|12|1|13]]|E|$]]|$1|M|3|N|5|6|7|14|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

With Jackson (<code>com.fasterxml.jackson.databind</code>):

<pre class="lang-java prettyprint-override"><code>ObjectMapper mapper = new ObjectMapper();
System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonObject))
</code></pre>

From: <a href="https://www.mkyong.com/java/how-to-enable-pretty-print-json-output-jackson/" rel="noreferrer">How to enable pretty print JSON output (Jackson)</a>

I know this is already in the answers, but I want to write it separately here because chances are, you already have Jackson as a dependency and so all you will need would be an extra line of code

blocks|key|1099581|text|看起来GSON支持这一点，尽管我不知道你是否想要从你正在使用的库中切换。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1099582|从用户指南中：|1099583|Gson+gson+=+new+GsonBuilder().setPrettyPrinting().create();
String+jsonOutput+=+gson.toJson(someObject);|code-block|syntax|javascript|1099584|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/google/gson^0|3|4|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

It seems like <a href="https://github.com/google/gson" rel="noreferrer">GSON</a> supports this, although I don't know if you want to switch from the library you are using.

From the user guide:

<pre><code>Gson gson = new GsonBuilder().setPrettyPrinting().create();
String jsonOutput = gson.toJson(someObject);
</code></pre>

blocks|key|885048|text|如果使用Java+API+for+JSON+Processing+(JSR-353)实现，那么可以在创建JsonGeneratorFactory时指定JsonGenerator.PRETTY_PRINTING属性。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|885049|以下示例最初是在我的blog+post上发布的。|885050|import+java.util.*;
import+javax.json.Json;
import+javax.json.stream.*;

Map<String,+Object>+properties+=+new+HashMap<String,+Object>(1);
properties.put(JsonGenerator.PRETTY_PRINTING,+true);
JsonGeneratorFactory+jgf+=+Json.createGeneratorFactory(properties);
JsonGenerator+jg+=+jgf.createGenerator(System.out);

jg.writeStartObject()++++++++++++++++++++//+{
++++.write("name",+"Jane+Doe")+++++++++++//++++"name":"Jane+Doe",
++++.writeStartObject("address")+++++++++//++++"address":{
++++++++.write("type",+1)++++++++++++++++//++++++++"type":1,
++++++++.write("street",+"1+A+Street")+++//++++++++"street":"1+A+Street",
++++++++.writeNull("city")+++++++++++++++//++++++++"city":null,
++++++++.write("verified",+false)++++++++//++++++++"verified":false
++++.writeEnd()++++++++++++++++++++++++++//++++},
++++.writeStartArray("phone-numbers")++++//++++"phone-numbers":[
++++++++.writeStartObject()++++++++++++++//++++++++{
++++++++++++.write("number",+"555-1111")+//++++++++++++"number":"555-1111",
++++++++++++.write("extension",+"123")+++//++++++++++++"extension":"123"
++++++++.writeEnd()++++++++++++++++++++++//++++++++},
++++++++.writeStartObject()++++++++++++++//++++++++{
++++++++++++.write("number",+"555-2222")+//++++++++++++"number":"555-2222",
++++++++++++.writeNull("extension")++++++//++++++++++++"extension":null
++++++++.writeEnd()++++++++++++++++++++++//++++++++}
++++.writeEnd()++++++++++++++++++++++++++//++++]
.writeEnd()++++++++++++++++++++++++++++++//+}
.close();|code-block|syntax|javascript|885051|entityMap|0|LINK|mutability|MUTABLE|url|http://blog.bdoughan.com/2013/04/java-api-for-json-processing-jsr-353.html^0|1G|K|23|T|0|A|9|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@]|D|@$9|10|A|11|1|12]]|E|$]]|$1|H|3|I|5|J|7|13|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

If you are using a Java API for JSON Processing (JSR-353) implementation then you can specify the <code>JsonGenerator.PRETTY_PRINTING</code> property when you create a <code>JsonGeneratorFactory</code>.

The following example has been originally published on my <a href="http://blog.bdoughan.com/2013/04/java-api-for-json-processing-jsr-353.html" rel="noreferrer">blog post</a>.

<pre><code>import java.util.*;
import javax.json.Json;
import javax.json.stream.*;

Map&lt;String, Object&gt; properties = new HashMap&lt;String, Object&gt;(1);
properties.put(JsonGenerator.PRETTY_PRINTING, true);
JsonGeneratorFactory jgf = Json.createGeneratorFactory(properties);
JsonGenerator jg = jgf.createGenerator(System.out);

jg.writeStartObject() // {
 .write("name", "Jane Doe") // "name":"Jane Doe",
 .writeStartObject("address") // "address":{
 .write("type", 1) // "type":1,
 .write("street", "1 A Street") // "street":"1 A Street",
 .writeNull("city") // "city":null,
 .write("verified", false) // "verified":false
 .writeEnd() // },
 .writeStartArray("phone-numbers") // "phone-numbers":[
 .writeStartObject() // {
 .write("number", "555-1111") // "number":"555-1111",
 .write("extension", "123") // "extension":"123"
 .writeEnd() // },
 .writeStartObject() // {
 .write("number", "555-2222") // "number":"555-2222",
 .writeNull("extension") // "extension":null
 .writeEnd() // }
 .writeEnd() // ]
.writeEnd() // }
.close();
</code></pre>

blocks|key|1099804|text|在一行代码中使用GSON进行漂亮的打印：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1099805|System.out.println(new+GsonBuilder().setPrettyPrinting().create().toJson(new+JsonParser().parse(jsonString)));|code-block|syntax|javascript|1099806|除了内联，这相当于the+accepted+answer。|1099807|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/google/gson|1|https://stackoverflow.com/a/7310424/906658^0|8|4|0|0|0|9|J|1|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|K|3|-4|5|6|7|13|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]|S|$5|N|O|P|C|$Q|T]]]]

Pretty printing with <a href="https://github.com/google/gson" rel="noreferrer">GSON</a> in one line:

<pre><code>System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(new JsonParser().parse(jsonString)));
</code></pre>

Besides inlining, this is equivalent to <a href="https://stackoverflow.com/a/7310424/906658">the accepted answer</a>.

blocks|key|1100009|text|我的情况是我的项目使用了一个遗留的(非JSR)+JSON解析器，它不支持漂亮的打印。但是，我需要生成打印得很好的JSON示例；只要您使用的是Java+7或更高版本，就可以在不添加任何额外的库的情况下实现这一点：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1100010|ScriptEngineManager+manager+=+new+ScriptEngineManager();
ScriptEngine+scriptEngine+=+manager.getEngineByName("JavaScript");
scriptEngine.put("jsonString",+jsonStringNoWhitespace);
scriptEngine.eval("result+=+JSON.stringify(JSON.parse(jsonString),+null,+2)");
String+prettyPrintedJson+=+(String)+scriptEngine.get("result");|code-block|syntax|javascript|1100011|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

My situation is my project uses a legacy (non-JSR) JSON parser that does not support pretty printing. However, I needed to produce pretty-printed JSON samples; this is possible without having to add any extra libraries as long as you are using Java 7 and above:

<pre><code>ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine scriptEngine = manager.getEngineByName("JavaScript");
scriptEngine.put("jsonString", jsonStringNoWhitespace);
scriptEngine.eval("result = JSON.stringify(JSON.parse(jsonString), null, 2)");
String prettyPrintedJson = (String) scriptEngine.get("result");
</code></pre>

blocks|key|1100427|text|使用org+json。参考link|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1100428|JSONObject+jsonObject+=+new+JSONObject(obj);
String+prettyJson+=+jsonObject.toString(4);|code-block|syntax|javascript|1100429|使用Gson。参考link|1100430|Gson+gson+=+new+GsonBuilder().setPrettyPrinting().create();
String+json+=+gson.toJson(obj);|1100431|利用杰克逊。参考link|1100432|ObjectMapper+mapper+=+new+ObjectMapper();
mapper.enable(SerializationFeature.INDENT_OUTPUT);
String+json+=+mapper.writeValueAsString(obj);|1100433|使用Genson。参考link。|1100434|Genson+prettyGenson+=+new+GensonBuilder().useIndentation(true).create();
String+prettyJson+=+prettyGenson.serialize(obj);|1100435|使用javax.json。参考link。|1100436|Map<String,+Boolean>+config+=+new+HashMap<>();

config.put(JsonGenerator.PRETTY_PRINTING,+true);

JsonWriterFactory+writerFactory+=+Json.createWriterFactory(config);
Writer+writer+=+new+StringWriter();

writerFactory.createWriter(writer).write(jsonObject);

String+json+=+writer.toString();|1100437|使用Moshi库。参考link。|1100438|String+json+=+jsonAdapter.indent("++").toJson(emp1);|1100439|(或)|1100440|Buffer+buffer+=+new+Buffer();
JsonWriter+jsonWriter+=+JsonWriter.of(buffer);
jsonWriter.setIndent("+++");

jsonAdapter.toJson(jsonWriter,+emp1);

json+=+buffer.readUtf8();|1100441|entityMap|0|LINK|mutability|MUTABLE|url|https://self-learning-java-tutorial.blogspot.com/2020/02/org-json-pretty-print-json.html|1|https://self-learning-java-tutorial.blogspot.com/2014/11/pretty-print-json-format.html|2|https://self-learning-java-tutorial.blogspot.com/2015/10/jackson-pretty-print-json.html|3|https://self-learning-java-tutorial.blogspot.com/2016/04/genson-pretty-json.html|4|https://self-learning-java-tutorial.blogspot.com/2021/03/javaxjson-pretty-print-json.html|5|https://self-learning-java-tutorial.blogspot.com/2021/06/moshi-pretty-print-json.html^0|D|4|0|0|0|9|4|1|0|0|8|4|2|0|0|B|4|3|0|0|F|4|4|0|0|B|4|5|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1O|8|@]|9|@$A|1P|B|1Q|1|1R]]|C|$]]|$1|D|3|E|5|F|7|1S|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|1T|8|@]|9|@$A|1U|B|1V|1|1W]]|C|$]]|$1|K|3|L|5|F|7|1X|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|1Y|8|@]|9|@$A|1Z|B|20|1|21]]|C|$]]|$1|O|3|P|5|F|7|22|8|@]|9|@]|C|$G|H]]|$1|Q|3|R|5|6|7|23|8|@]|9|@$A|24|B|25|1|26]]|C|$]]|$1|S|3|T|5|F|7|27|8|@]|9|@]|C|$G|H]]|$1|U|3|V|5|6|7|28|8|@]|9|@$A|29|B|2A|1|2B]]|C|$]]|$1|W|3|X|5|F|7|2C|8|@]|9|@]|C|$G|H]]|$1|Y|3|Z|5|6|7|2D|8|@]|9|@$A|2E|B|2F|1|2G]]|C|$]]|$1|10|3|11|5|F|7|2H|8|@]|9|@]|C|$G|H]]|$1|12|3|13|5|6|7|2I|8|@]|9|@]|C|$]]|$1|14|3|15|5|F|7|2J|8|@]|9|@]|C|$G|H]]|$1|16|3|-4|5|6|7|2K|8|@]|9|@]|C|$]]]|17|$18|$5|19|1A|1B|C|$1C|1D]]|1E|$5|19|1A|1B|C|$1C|1F]]|1G|$5|19|1A|1B|C|$1C|1H]]|1I|$5|19|1A|1B|C|$1C|1J]]|1K|$5|19|1A|1B|C|$1C|1L]]|1M|$5|19|1A|1B|C|$1C|1N]]]]

Using org json. Reference <a href="https://self-learning-java-tutorial.blogspot.com/2020/02/org-json-pretty-print-json.html" rel="noreferrer">link</a>
<pre><code>JSONObject jsonObject = new JSONObject(obj);
String prettyJson = jsonObject.toString(4);
</code></pre>
Using Gson. Reference <a href="https://self-learning-java-tutorial.blogspot.com/2014/11/pretty-print-json-format.html" rel="noreferrer">link</a>
<pre><code>Gson gson = new GsonBuilder().setPrettyPrinting().create();
String json = gson.toJson(obj);
</code></pre>
Using Jackson. Reference <a href="https://self-learning-java-tutorial.blogspot.com/2015/10/jackson-pretty-print-json.html" rel="noreferrer">link</a>
<pre><code>ObjectMapper mapper = new ObjectMapper();
mapper.enable(SerializationFeature.INDENT_OUTPUT);
String json = mapper.writeValueAsString(obj);
</code></pre>
Using Genson. Reference <a href="https://self-learning-java-tutorial.blogspot.com/2016/04/genson-pretty-json.html" rel="noreferrer">link</a>.
<pre><code>Genson prettyGenson = new GensonBuilder().useIndentation(true).create();
String prettyJson = prettyGenson.serialize(obj);
</code></pre>
Using javax.json. Reference <a href="https://self-learning-java-tutorial.blogspot.com/2021/03/javaxjson-pretty-print-json.html" rel="noreferrer">link</a>.
<pre><code>Map&lt;String, Boolean&gt; config = new HashMap&lt;&gt;();

config.put(JsonGenerator.PRETTY_PRINTING, true);

JsonWriterFactory writerFactory = Json.createWriterFactory(config);
Writer writer = new StringWriter();

writerFactory.createWriter(writer).write(jsonObject);

String json = writer.toString();
</code></pre>
Using Moshi library. Reference <a href="https://self-learning-java-tutorial.blogspot.com/2021/06/moshi-pretty-print-json.html" rel="noreferrer">link</a>.
<pre><code>String json = jsonAdapter.indent(&quot; &quot;).toJson(emp1);
</code></pre>
(OR)
<pre><code>Buffer buffer = new Buffer();
JsonWriter jsonWriter = JsonWriter.of(buffer);
jsonWriter.setIndent(&quot; &quot;);

jsonAdapter.toJson(jsonWriter, emp1);

json = buffer.readUtf8();
</code></pre>

blocks|key|1100293|text|现有的大多数答案要么依赖于一些外部库，要么需要特殊的Java版本。下面是一个简单的代码，可以很好地打印一个JSON字符串，只使用一般的Java+API(在Java+7中有更高版本；虽然没有尝试过旧版本)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1100294|其基本思想是在JSON中触发基于特殊字符的格式化。例如，如果观察到'{‘或'[’，代码将创建一个新行并增加缩进级别。|1100295|免责声明:我只对一些简单的JSON用例(基本键值对、列表、嵌套JSON)进行了测试，所以对于更一般的JSON文本，可能需要做一些工作，比如包含引号的字符串值，或者特殊字符(\n、\t等)。|1100296|/**
+*+A+simple+implementation+to+pretty-print+JSON+file.
+*
+*+@param+unformattedJsonString
+*+@return
+*/
public+static+String+prettyPrintJSON(String+unformattedJsonString)+{
++StringBuilder+prettyJSONBuilder+=+new+StringBuilder();
++int+indentLevel+=+0;
++boolean+inQuote+=+false;
++for(char+charFromUnformattedJson+:+unformattedJsonString.toCharArray())+{
++++switch(charFromUnformattedJson)+{
++++++case+'"':
++++++++//+switch+the+quoting+status
++++++++inQuote+=+!inQuote;
++++++++prettyJSONBuilder.append(charFromUnformattedJson);
++++++++break;
++++++case+'+':
++++++++//+For+space:+ignore+the+space+if+it+is+not+being+quoted.
++++++++if(inQuote)+{
++++++++++prettyJSONBuilder.append(charFromUnformattedJson);
++++++++}
++++++++break;
++++++case+'{':
++++++case+'[':
++++++++//+Starting+a+new+block:+increase+the+indent+level
++++++++prettyJSONBuilder.append(charFromUnformattedJson);
++++++++indentLevel%2B%2B;
++++++++appendIndentedNewLine(indentLevel,+prettyJSONBuilder);
++++++++break;
++++++case+'}':
++++++case+']':
++++++++//+Ending+a+new+block;+decrese+the+indent+level
++++++++indentLevel--;
++++++++appendIndentedNewLine(indentLevel,+prettyJSONBuilder);
++++++++prettyJSONBuilder.append(charFromUnformattedJson);
++++++++break;
++++++case+',':
++++++++//+Ending+a+json+item;+create+a+new+line+after
++++++++prettyJSONBuilder.append(charFromUnformattedJson);
++++++++if(!inQuote)+{
++++++++++appendIndentedNewLine(indentLevel,+prettyJSONBuilder);
++++++++}
++++++++break;
++++++default:
++++++++prettyJSONBuilder.append(charFromUnformattedJson);
++++}
++}
++return+prettyJSONBuilder.toString();
}

/**
+*+Print+a+new+line+with+indention+at+the+beginning+of+the+new+line.
+*+@param+indentLevel
+*+@param+stringBuilder
+*/
private+static+void+appendIndentedNewLine(int+indentLevel,+StringBuilder+stringBuilder)+{
++stringBuilder.append("\n");
++for(int+i+=+0;+i+<+indentLevel;+i%2B%2B)+{
++++//+Assuming+indention+using+2+spaces
++++stringBuilder.append("++");
++}
}|code-block|syntax|javascript|1100297|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Most of the existing answers either depend on some external library, or requiring a special Java version. Here is a simple code to pretty print a JSON string, only using general Java APIs (available in Java 7 for higher; haven't tried older version although).

The basic idea is to tigger the formatting based on special characters in JSON. For example, if a '{' or '[' is observed, the code will create a new line and increase the indent level.

Disclaimer: I only tested this for some simple JSON cases (basic key-value pair, list, nested JSON) so it may need some work for more general JSON text, like string value with quotes inside, or special characters (\n, \t etc.).

<pre><code>/**
 * A simple implementation to pretty-print JSON file.
 *
 * @param unformattedJsonString
 * @return
 */
public static String prettyPrintJSON(String unformattedJsonString) {
 StringBuilder prettyJSONBuilder = new StringBuilder();
 int indentLevel = 0;
 boolean inQuote = false;
 for(char charFromUnformattedJson : unformattedJsonString.toCharArray()) {
 switch(charFromUnformattedJson) {
 case '"':
 // switch the quoting status
 inQuote = !inQuote;
 prettyJSONBuilder.append(charFromUnformattedJson);
 break;
 case ' ':
 // For space: ignore the space if it is not being quoted.
 if(inQuote) {
 prettyJSONBuilder.append(charFromUnformattedJson);
 }
 break;
 case '{':
 case '[':
 // Starting a new block: increase the indent level
 prettyJSONBuilder.append(charFromUnformattedJson);
 indentLevel++;
 appendIndentedNewLine(indentLevel, prettyJSONBuilder);
 break;
 case '}':
 case ']':
 // Ending a new block; decrese the indent level
 indentLevel--;
 appendIndentedNewLine(indentLevel, prettyJSONBuilder);
 prettyJSONBuilder.append(charFromUnformattedJson);
 break;
 case ',':
 // Ending a json item; create a new line after
 prettyJSONBuilder.append(charFromUnformattedJson);
 if(!inQuote) {
 appendIndentedNewLine(indentLevel, prettyJSONBuilder);
 }
 break;
 default:
 prettyJSONBuilder.append(charFromUnformattedJson);
 }
 }
 return prettyJSONBuilder.toString();
}

/**
 * Print a new line with indention at the beginning of the new line.
 * @param indentLevel
 * @param stringBuilder
 */
private static void appendIndentedNewLine(int indentLevel, StringBuilder stringBuilder) {
 stringBuilder.append("\n");
 for(int i = 0; i &lt; indentLevel; i++) {
 // Assuming indention using 2 spaces
 stringBuilder.append(" ");
 }
}
</code></pre>

blocks|key|885110|text|现在，这可以通过JSONLib库来实现：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|885111|http://json-lib.sourceforge.net/apidocs/net/sf/json/JSONObject.html|offset|length|885112|当(且仅当)您使用重载的toString(int+indentationFactor)方法，而不是标准的toString()方法。|style|CODE|885113|我已经在以下版本的API上验证了这一点：|885114|<dependency>
++<groupId>org.json</groupId>
++<artifactId>json</artifactId>
++<version>20140107</version>
</dependency>|code-block|syntax|javascript|885115|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1V|0|0|C|V|1G|A|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Y|8|@]|9|@$D|Z|E|10|1|11]]|A|$]]|$1|F|3|G|5|6|7|12|8|@$D|13|E|14|H|I]|$D|15|E|16|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|17|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|18|8|@]|9|@]|A|$O|P]]|$1|Q|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|C]]]]

Now this can be achieved with the JSONLib library:

<a href="http://json-lib.sourceforge.net/apidocs/net/sf/json/JSONObject.html" rel="noreferrer">http://json-lib.sourceforge.net/apidocs/net/sf/json/JSONObject.html</a>

If (and only if) you use the overloaded <code>toString(int indentationFactor)</code> method and not the standard <code>toString()</code> method.

I have verified this on the following version of the API:

<pre class="lang-xml prettyprint-override"><code>&lt;dependency&gt;
 &lt;groupId&gt;org.json&lt;/groupId&gt;
 &lt;artifactId&gt;json&lt;/artifactId&gt;
 &lt;version&gt;20140107&lt;/version&gt;
&lt;/dependency&gt;
</code></pre>

blocks|key|885167|text|在一行代码中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|885168|String+niceFormattedJson+=+JsonWriter.formatJson(jsonString)|code-block|syntax|javascript|885169|json-io+libray+(https://github.com/jdereg/json-io)是一个小的(75K)库，除了JDK之外没有其他依赖项。|offset|length|885170|除了漂亮地打印JSON之外，您还可以将Java对象(带循环的整个Java对象图)序列化为JSON，并读取它们。|885171|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/jdereg/json-io^0|0|0|G|X|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@$I|X|J|Y|1|Z]]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

In one line:

<pre><code>String niceFormattedJson = JsonWriter.formatJson(jsonString)
</code></pre>

The json-io libray (<a href="https://github.com/jdereg/json-io" rel="noreferrer">https://github.com/jdereg/json-io</a>) is a small (75K) library with no other dependencies than the JDK. 

In addition to pretty-printing JSON, you can serialize Java objects (entire Java object graphs with cycles) to JSON, as well as read them in.

blocks|key|884942|text|在JSONLib中，您可以使用以下命令：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|884943|String+jsonTxt+=+JSONUtils.valueToString(json,+8,+4);|code-block|syntax|javascript|884944|从Javadoc|offset|length|884945|​|884946|📷|atomic|884947|884948|entityMap|0|LINK|mutability|MUTABLE|url|http://json-lib.sourceforge.net/apidocs/jdk15/net/sf/json/util/JSONUtils.html#valueToString(java.lang.Object,%2520int,%2520int))|1|IMAGE|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/ce04c0b23a2e893590da73599ad6725b.png|imageAlt^0|0|0|1|7|0|0|0|0|1|1|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|16|8|@]|9|@$I|17|J|18|1|19]]|A|$]]|$1|K|3|L|5|6|7|1A|8|@]|9|@]|A|$]]|$1|M|3|N|5|O|7|1B|8|@]|9|@$I|1C|J|1D|1|1E]]|A|$]]|$1|P|3|L|5|6|7|1F|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]|Y|$5|Z|U|10|A|$11|12|13|-4]]]]

In JSONLib you can use this:

<pre><code>String jsonTxt = JSONUtils.valueToString(json, 8, 4);
</code></pre>

From the <a href="http://json-lib.sourceforge.net/apidocs/jdk15/net/sf/json/util/JSONUtils.html#valueToString(java.lang.Object,%20int,%20int)" rel="noreferrer">Javadoc</a>:

<a href="https://i.stack.imgur.com/pWzAc.png" rel="noreferrer"><img src="https://i.stack.imgur.com/pWzAc.png" alt=""></a>

blocks|key|885298|text|遵循JSON-P1.0规范(JSR-353)，针对给定JsonStructure+(JsonObject或JsonArray)的更新的解决方案可能如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|885299|import+java.io.StringWriter;
import+java.util.HashMap;
import+java.util.Map;

import+javax.json.Json;
import+javax.json.JsonStructure;
import+javax.json.JsonWriter;
import+javax.json.JsonWriterFactory;
import+javax.json.stream.JsonGenerator;

public+class+PrettyJson+{

++++private+static+JsonWriterFactory+FACTORY_INSTANCE;

++++public+static+String+toString(final+JsonStructure+status)+{

++++++++final+StringWriter+stringWriter+=+new+StringWriter();

++++++++final+JsonWriter+jsonWriter+=+getPrettyJsonWriterFactory()
++++++++++++++++.createWriter(stringWriter);

++++++++jsonWriter.write(status);
++++++++jsonWriter.close();

++++++++return+stringWriter.toString();
++++}

++++private+static+JsonWriterFactory+getPrettyJsonWriterFactory()+{
++++++++if+(null+==+FACTORY_INSTANCE)+{
++++++++++++final+Map<String,+Object>+properties+=+new+HashMap<>(1);
++++++++++++properties.put(JsonGenerator.PRETTY_PRINTING,+true);
++++++++++++FACTORY_INSTANCE+=+Json.createWriterFactory(properties);
++++++++}
++++++++return+FACTORY_INSTANCE;
++++}

}|code-block|syntax|javascript|885300|entityMap|0|LINK|mutability|MUTABLE|url|https://jcp.org/en/jsr/detail?id=353^0|R|D|16|A|1H|9|E|7|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

Following the JSON-P 1.0 specs (<a href="https://jcp.org/en/jsr/detail?id=353" rel="noreferrer">JSR-353</a>) a more current solution for a given <code>JsonStructure</code> (<code>JsonObject</code> or <code>JsonArray</code>) could look like this:

<pre><code>import java.io.StringWriter;
import java.util.HashMap;
import java.util.Map;

import javax.json.Json;
import javax.json.JsonStructure;
import javax.json.JsonWriter;
import javax.json.JsonWriterFactory;
import javax.json.stream.JsonGenerator;

public class PrettyJson {

 private static JsonWriterFactory FACTORY_INSTANCE;

 public static String toString(final JsonStructure status) {

 final StringWriter stringWriter = new StringWriter();

 final JsonWriter jsonWriter = getPrettyJsonWriterFactory()
 .createWriter(stringWriter);

 jsonWriter.write(status);
 jsonWriter.close();

 return stringWriter.toString();
 }

 private static JsonWriterFactory getPrettyJsonWriterFactory() {
 if (null == FACTORY_INSTANCE) {
 final Map&lt;String, Object&gt; properties = new HashMap&lt;&gt;(1);
 properties.put(JsonGenerator.PRETTY_PRINTING, true);
 FACTORY_INSTANCE = Json.createWriterFactory(properties);
 }
 return FACTORY_INSTANCE;
 }

}
</code></pre>

blocks|key|885338|text|你可以像下面这样使用Gson|type|unstyled|depth|inlineStyleRanges|entityRanges|data|885339|Gson+gson+=+new+GsonBuilder().setPrettyPrinting().create();
String+jsonString+=+gson.toJson(object);|code-block|syntax|javascript|885340|来自JSON+pretty+print+using+Gson的帖子|offset|length|885341|或者，你可以像下面这样使用Jackson|885342|ObjectMapper+mapper+=+new+ObjectMapper();
String+perttyStr+=+mapper.writerWithDefaultPrettyPrinter().writeValueAsString(object);|885343|来自Pretty+print+JSON+in+Java+(Jackson)的帖子|885344|希望这对你有所帮助！|885345|entityMap|0|LINK|mutability|MUTABLE|url|http://javabycode.com/java-core/json-tutorial/json-pretty-print-using-gson.html|1|http://javabycode.com/java-core/json-tutorial/pretty-print-json-in-java-jackson.html^0|0|0|2|S|0|0|0|0|2|Z|1|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|14|8|@]|9|@$I|15|J|16|1|17]]|A|$]]|$1|K|3|L|5|6|7|18|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|19|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|1A|8|@]|9|@$I|1B|J|1C|1|1D]]|A|$]]|$1|Q|3|R|5|6|7|1E|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]|10|$5|V|W|X|A|$Y|11]]]]

You can use Gson like below

<pre><code>Gson gson = new GsonBuilder().setPrettyPrinting().create();
String jsonString = gson.toJson(object);
</code></pre>

From the post <a href="http://javabycode.com/java-core/json-tutorial/json-pretty-print-using-gson.html" rel="noreferrer">JSON pretty print using Gson</a>

Alternatively, You can use Jackson like below

<pre><code>ObjectMapper mapper = new ObjectMapper();
String perttyStr = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(object);
</code></pre>

From the post <a href="http://javabycode.com/java-core/json-tutorial/pretty-print-json-in-java-jackson.html" rel="noreferrer">Pretty print JSON in Java (Jackson)</a>

Hope this help!

blocks|key|1100225|text|这对我很有效，使用Jackson：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1100226|mapper.writerWithDefaultPrettyPrinter().writeValueAsString(JSONString)|code-block|syntax|javascript|1100227|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This worked for me, using Jackson:

<pre><code>mapper.writerWithDefaultPrettyPrinter().writeValueAsString(JSONString)
</code></pre>

blocks|key|885596|text|你可以使用小的json库|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|885597|String+jsonstring+=+....;
JsonValue+json+=+JsonParser.parse(jsonstring);
String+jsonIndendedByTwoSpaces+=+json.toPrettyString("++");|code-block|syntax|javascript|885598|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/antonsjava/json^0|7|4|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

You can use small <a href="https://github.com/antonsjava/json" rel="nofollow noreferrer">json</a> library 

<pre><code>String jsonstring = ....;
JsonValue json = JsonParser.parse(jsonstring);
String jsonIndendedByTwoSpaces = json.toPrettyString(" ");
</code></pre>

blocks|key|885551|text|Underscore-java有静态方法U.formatJson(json)。支持5种格式:+2、3、4、制表符、紧凑。Live+example|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|885552|import+com.github.underscore.lodash.U;

import+static+com.github.underscore.lodash.Json.JsonStringBuilder.Step.TABS;
import+static+com.github.underscore.lodash.Json.JsonStringBuilder.Step.TWO_SPACES;

public+class+MyClass+{

++++public+static+void+main(String+args[])+{
++++++++String+json+=+"{\"Price\":+{"
++++++++%2B+"++++\"LineItems\":+{"
++++++++%2B+"++++++++\"LineItem\":+{"
++++++++%2B+"++++++++++++\"UnitOfMeasure\":+\"EACH\",+\"Quantity\":+2,+\"ItemID\":+\"ItemID\""
++++++++%2B+"++++++++}"
++++++++%2B+"++++},"
++++++++%2B+"++++\"Currency\":+\"USD\","
++++++++%2B+"++++\"EnterpriseCode\":+\"EnterpriseCode\""
++++++++%2B+"}}";
++++++++System.out.println(U.formatJson(json,+TWO_SPACES));+
++++++++System.out.println(U.formatJson(json,+TABS));+
++++}
}|code-block|syntax|javascript|885553|输出：|885554|{
++"Price":+{
++++"LineItems":+{
++++++"LineItem":+{
++++++++"UnitOfMeasure":+"EACH",
++++++++"Quantity":+2,
++++++++"ItemID":+"ItemID"
++++++}
++++},
++++"Currency":+"USD",
++++"EnterpriseCode":+"EnterpriseCode"
++}
}
{
++++"Price":+{
++++++++"LineItems":+{
++++++++++++"LineItem":+{
++++++++++++++++"UnitOfMeasure":+"EACH",
++++++++++++++++"Quantity":+2,
++++++++++++++++"ItemID":+"ItemID"
++++++++++++}
++++++++},
++++++++"Currency":+"USD",
++++++++"EnterpriseCode":+"EnterpriseCode"
++++}
}|885555|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/javadev/underscore-java|1|https://www.jdoodle.com/embed/v0/XrW^0|K|I|0|F|0|1O|C|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@$9|11|A|12|1|13]|$9|14|A|15|1|16]]|E|$]]|$1|F|3|G|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|18|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|19|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|1A|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]|W|$5|R|S|T|E|$U|X]]]]

<a href="https://github.com/javadev/underscore-java" rel="nofollow noreferrer">Underscore-java</a> has static method <code>U.formatJson(json)</code>.
Five format types are supported: 2, 3, 4, tabs and compact. <a href="https://www.jdoodle.com/embed/v0/XrW" rel="nofollow noreferrer">Live example</a>
<pre class="lang-java prettyprint-override"><code>import com.github.underscore.lodash.U;

import static com.github.underscore.lodash.Json.JsonStringBuilder.Step.TABS;
import static com.github.underscore.lodash.Json.JsonStringBuilder.Step.TWO_SPACES;

public class MyClass {

 public static void main(String args[]) {
 String json = &quot;{\&quot;Price\&quot;: {&quot;
 + &quot; \&quot;LineItems\&quot;: {&quot;
 + &quot; \&quot;LineItem\&quot;: {&quot;
 + &quot; \&quot;UnitOfMeasure\&quot;: \&quot;EACH\&quot;, \&quot;Quantity\&quot;: 2, \&quot;ItemID\&quot;: \&quot;ItemID\&quot;&quot;
 + &quot; }&quot;
 + &quot; },&quot;
 + &quot; \&quot;Currency\&quot;: \&quot;USD\&quot;,&quot;
 + &quot; \&quot;EnterpriseCode\&quot;: \&quot;EnterpriseCode\&quot;&quot;
 + &quot;}}&quot;;
 System.out.println(U.formatJson(json, TWO_SPACES)); 
 System.out.println(U.formatJson(json, TABS)); 
 }
}
</code></pre>
Output:
<pre class="lang-json prettyprint-override"><code>{
 &quot;Price&quot;: {
 &quot;LineItems&quot;: {
 &quot;LineItem&quot;: {
 &quot;UnitOfMeasure&quot;: &quot;EACH&quot;,
 &quot;Quantity&quot;: 2,
 &quot;ItemID&quot;: &quot;ItemID&quot;
 }
 },
 &quot;Currency&quot;: &quot;USD&quot;,
 &quot;EnterpriseCode&quot;: &quot;EnterpriseCode&quot;
 }
}
{
 &quot;Price&quot;: {
 &quot;LineItems&quot;: {
 &quot;LineItem&quot;: {
 &quot;UnitOfMeasure&quot;: &quot;EACH&quot;,
 &quot;Quantity&quot;: 2,
 &quot;ItemID&quot;: &quot;ItemID&quot;
 }
 },
 &quot;Currency&quot;: &quot;USD&quot;,
 &quot;EnterpriseCode&quot;: &quot;EnterpriseCode&quot;
 }
}
</code></pre>

I'm using <a href="/questions/tagged/json-simple" class="post-tag" title="show questions tagged &#39;json-simple&#39;" rel="tag">json-simple</a> and I need to pretty-print JSON data (make it more human readable).

I haven't been able to find this functionality within that library.
How is this commonly achieved?

Pretty-Print JSON in Java

我正在使用，并且我需要漂亮地打印JSON数据(使其更具人类可读性)。我还没能在那个库中找到这个功能。这通常是如何实现的？

问Java中的漂亮打印JSON
EN

回答 17

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