blocks|key|807247|text|如果您需要Base64+over+JSON，请查看Jackson：它在低级(JsonParser、JsonGenerator)和数据绑定级别都明确支持以Base64格式读/写二进制数据。因此，您可以只使用具有byte[]属性的POJOs，并自动处理编码/解码。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|807248|而且效率也很高，如果这很重要的话。|807249|entityMap|0|LINK|mutability|MUTABLE|url|http://wiki.fasterxml.com/JacksonInFiveMinutes|1|https://en.wikipedia.org/wiki/Plain_Old_Java_Object^0|P|7|0|35|5|1|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]|$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|X|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]]]

If you need Base64 over JSON, check out <a href="http://wiki.fasterxml.com/JacksonInFiveMinutes" rel="nofollow noreferrer">Jackson</a>: it has explicit support for binary data read/write as Base64 at both the low level (JsonParser, JsonGenerator) and data-binding level. So you can just have <a href="https://en.wikipedia.org/wiki/Plain_Old_Java_Object" rel="nofollow noreferrer">POJOs</a> with byte[] properties, and encoding/decoding is automatically handled.

And pretty efficiently too, should that matter.

blocks|key|807303|text|除了使用Bitmap，您还可以通过一个简单的InputStream来实现这一点。嗯，我不确定，但我认为它有点效率。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|807304|InputStream+inputStream+=+new+FileInputStream(fileName);+//+You+can+get+an+inputStream+using+any+I/O+API
byte[]+bytes;
byte[]+buffer+=+new+byte[8192];
int+bytesRead;
ByteArrayOutputStream+output+=+new+ByteArrayOutputStream();

try+{
++++while+((bytesRead+=+inputStream.read(buffer))+!=+-1)+{
++++++++output.write(buffer,+0,+bytesRead);
++++}
}
catch+(IOException+e)+{
++++e.printStackTrace();
}

bytes+=+output.toByteArray();
String+encodedString+=+Base64.encodeToString(bytes,+Base64.DEFAULT);|code-block|syntax|javascript|807305|entityMap^0|4|6|M|B|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Instead of using <code>Bitmap</code>, you can also do this through a trivial <code>InputStream</code>. Well, I am not sure, but I think it's a bit efficient.

<pre><code>InputStream inputStream = new FileInputStream(fileName); // You can get an inputStream using any I/O API
byte[] bytes;
byte[] buffer = new byte[8192];
int bytesRead;
ByteArrayOutputStream output = new ByteArrayOutputStream();

try {
 while ((bytesRead = inputStream.read(buffer)) != -1) {
 output.write(buffer, 0, bytesRead);
 }
}
catch (IOException e) {
 e.printStackTrace();
}

bytes = output.toByteArray();
String encodedString = Base64.encodeToString(bytes, Base64.DEFAULT);
</code></pre>

blocks|key|807368|text|这段代码在我的项目中运行得很好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|807369|profile_image.buildDrawingCache();
Bitmap+bmap+=+profile_image.getDrawingCache();
String+encodedImageData+=+getEncoded64ImageStringFromBitmap(bmap);


public+String+getEncoded64ImageStringFromBitmap(Bitmap+bitmap)+{
++++ByteArrayOutputStream+stream+=+new+ByteArrayOutputStream();
++++bitmap.compress(CompressFormat.JPEG,+70,+stream);
++++byte[]+byteFormat+=+stream.toByteArray();

++++//+Get+the+Base64+string
++++String+imgString+=+Base64.encodeToString(byteFormat,+Base64.NO_WRAP);

++++return+imgString;
}|code-block|syntax|javascript|807370|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 code runs perfect in my project:

<pre><code>profile_image.buildDrawingCache();
Bitmap bmap = profile_image.getDrawingCache();
String encodedImageData = getEncoded64ImageStringFromBitmap(bmap);


public String getEncoded64ImageStringFromBitmap(Bitmap bitmap) {
 ByteArrayOutputStream stream = new ByteArrayOutputStream();
 bitmap.compress(CompressFormat.JPEG, 70, stream);
 byte[] byteFormat = stream.toByteArray();

 // Get the Base64 string
 String imgString = Base64.encodeToString(byteFormat, Base64.NO_WRAP);

 return imgString;
}
</code></pre>

blocks|key|1022113|text|byte[]+decodedString+=+Base64.decode(result.getBytes(),+Base64.DEFAULT);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1022114|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>byte[] decodedString = Base64.decode(result.getBytes(), Base64.DEFAULT);
</code></pre>

blocks|key|1022126|text|//+Put+the+image+file+path+into+this+method
public+static+String+getFileToByte(String+filePath){
++++Bitmap+bmp+=+null;
++++ByteArrayOutputStream+bos+=+null;
++++byte[]+bt+=+null;
++++String+encodeString+=+null;
++++try{
++++++++bmp+=+BitmapFactory.decodeFile(filePath);
++++++++bos+=+new+ByteArrayOutputStream();
++++++++bmp.compress(Bitmap.CompressFormat.JPEG,+100,+bos);
++++++++bt+=+bos.toByteArray();
++++++++encodeString+=+Base64.encodeToString(bt,+Base64.DEFAULT);
++++}
++++catch+(Exception+e){
++++++e.printStackTrace();
++++}
++++return+encodeString;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1022127|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>// Put the image file path into this method
public static String getFileToByte(String filePath){
 Bitmap bmp = null;
 ByteArrayOutputStream bos = null;
 byte[] bt = null;
 String encodeString = null;
 try{
 bmp = BitmapFactory.decodeFile(filePath);
 bos = new ByteArrayOutputStream();
 bmp.compress(Bitmap.CompressFormat.JPEG, 100, bos);
 bt = bos.toByteArray();
 encodeString = Base64.encodeToString(bt, Base64.DEFAULT);
 }
 catch (Exception e){
 e.printStackTrace();
 }
 return encodeString;
}
</code></pre>

blocks|key|807423|text|使用以下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|807424|byte[]+decodedString+=+Base64.decode(Base64String.getBytes(),+Base64.DEFAULT);

Bitmap+decodedByte+=+BitmapFactory.decodeByteArray(decodedString,+0,+decodedString.length);|code-block|syntax|javascript|807425|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|$]]

Use this code:

<pre><code>byte[] decodedString = Base64.decode(Base64String.getBytes(), Base64.DEFAULT);

Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
</code></pre>

blocks|key|807484|text|下面是可能对您有帮助的伪代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|807485|public++String+getBase64FromFile(String+path)
{
++++Bitmap+bmp+=+null;
++++ByteArrayOutputStream+baos+=+null;
++++byte[]+baat+=+null;
++++String+encodeString+=+null;
++++try
++++{
++++++++bmp+=+BitmapFactory.decodeFile(path);
++++++++baos+=+new+ByteArrayOutputStream();
++++++++bmp.compress(Bitmap.CompressFormat.JPEG,+100,+baos);
++++++++baat+=+baos.toByteArray();
++++++++encodeString+=+Base64.encodeToString(baat,+Base64.DEFAULT);
++++}
++++catch+(Exception+e)
++++{
++++++++e.printStackTrace();
++++}

+++return+encodeString;
}|code-block|syntax|javascript|807486|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|$]]

Below is the pseudocode that may help you:

<pre><code>public String getBase64FromFile(String path)
{
 Bitmap bmp = null;
 ByteArrayOutputStream baos = null;
 byte[] baat = null;
 String encodeString = null;
 try
 {
 bmp = BitmapFactory.decodeFile(path);
 baos = new ByteArrayOutputStream();
 bmp.compress(Bitmap.CompressFormat.JPEG, 100, baos);
 baat = baos.toByteArray();
 encodeString = Base64.encodeToString(baat, Base64.DEFAULT);
 }
 catch (Exception e)
 {
 e.printStackTrace();
 }

 return encodeString;
}
</code></pre>

blocks|key|1022323|text|以下是用Kotlin编写的编码和解码代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1022324|+fun+encode(imageUri:+Uri):+String+{
++++val+input+=+activity.getContentResolver().openInputStream(imageUri)
++++val+image+=+BitmapFactory.decodeStream(input+,+null,+null)

++++//+Encode+image+to+base64+string
++++val+baos+=+ByteArrayOutputStream()
++++image.compress(Bitmap.CompressFormat.JPEG,+100,+baos)
++++var+imageBytes+=+baos.toByteArray()
++++val+imageString+=+Base64.encodeToString(imageBytes,+Base64.DEFAULT)
++++return+imageString
}

fun+decode(imageString:+String)+{

++++//+Decode+base64+string+to+image
++++val+imageBytes+=+Base64.decode(imageString,+Base64.DEFAULT)
++++val+decodedImage+=+BitmapFactory.decodeByteArray(imageBytes,+0,+imageBytes.size)

++++imageview.setImageBitmap(decodedImage)
}|code-block|syntax|javascript|1022325|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|$]]

Here is the encoding and decoding code in Kotlin:

<pre><code> fun encode(imageUri: Uri): String {
 val input = activity.getContentResolver().openInputStream(imageUri)
 val image = BitmapFactory.decodeStream(input , null, null)

 // Encode image to base64 string
 val baos = ByteArrayOutputStream()
 image.compress(Bitmap.CompressFormat.JPEG, 100, baos)
 var imageBytes = baos.toByteArray()
 val imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT)
 return imageString
}

fun decode(imageString: String) {

 // Decode base64 string to image
 val imageBytes = Base64.decode(imageString, Base64.DEFAULT)
 val decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size)

 imageview.setImageBitmap(decodedImage)
}
</code></pre>

blocks|key|1022369|text|在Android中将图片转换为Base64字符串：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1022370|ByteArrayOutputStream+baos+=+new+ByteArrayOutputStream();
Bitmap+bitmap+=+BitmapFactory.decodeResource(getResources(),+R.drawable.yourimage);
bitmap.compress(Bitmap.CompressFormat.JPEG,+100,+baos);
byte[]+imageBytes+=+baos.toByteArray();
String+imageString+=+Base64.encodeToString(imageBytes,+Base64.DEFAULT);|code-block|syntax|javascript|1022371|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|$]]

Convert an image to Base64 string in Android:

<pre><code>ByteArrayOutputStream baos = new ByteArrayOutputStream();
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.yourimage);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] imageBytes = baos.toByteArray();
String imageString = Base64.encodeToString(imageBytes, Base64.DEFAULT);
</code></pre>

blocks|key|807714|text|如果您正在寻找一种有效的方法来将图像文件转换为Base64字符串，而无需先将图像文件压缩或转换为位图，那么您可以使用encode+the+file+as+base64|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|807715|val+base64EncodedImage+=+FileInputStream(imageItem.localSrc).use+{inputStream+-+>
++++ByteArrayOutputStream().use+{outputStream+-+>
++++++++++++Base64OutputStream(outputStream,+Base64.DEFAULT).use+{
++++++++++++++++base64FilterStream+-+>
++++++++++++++++++++inputStream.copyTo(base64FilterStream)
++++++++++++++++base64FilterStream.flush()
++++++++++++++++outputStream.toString()
++++++++++++}
++++++}
}|code-block|syntax|javascript|807716|希望这能有所帮助！|807717|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/28758014/how-to-convert-a-file-to-base64^0|1M|P|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]]]]

For those looking for an efficient method to convert an image file to a Base64 string without compression or converting the file to a bitmap first, you can instead <a href="https://stackoverflow.com/questions/28758014/how-to-convert-a-file-to-base64">encode the file as base64</a> 

<pre><code>val base64EncodedImage = FileInputStream(imageItem.localSrc).use {inputStream - &gt;
 ByteArrayOutputStream().use {outputStream - &gt;
 Base64OutputStream(outputStream, Base64.DEFAULT).use {
 base64FilterStream - &gt;
 inputStream.copyTo(base64FilterStream)
 base64FilterStream.flush()
 outputStream.toString()
 }
 }
}
</code></pre>

Hope this helps!

blocks|key|807747|text|这是用于图像编码和图像解码的代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|807748|在XML文件中|807749|<TextView
++++android:layout_width="wrap_content"
++++android:layout_height="wrap_content"
++++android:text="yyuyuyuuyuyuyu"
++++android:id="@%2Bid/tv5"
/>|code-block|syntax|javascript|807750|在Java文件中：|807751|TextView+textView5;
Bitmap+bitmap;

textView5+=+(TextView)+findViewById(R.id.tv5);

bitmap+=+BitmapFactory.decodeResource(getResources(),+R.drawable.logo);

new+AsyncTask<Void,+Void,+String>()+{
++++@Override
++++protected+String+doInBackground(Void...+voids)+{
++++++++ByteArrayOutputStream+stream+=+new+ByteArrayOutputStream();
++++++++bitmap.compress(Bitmap.CompressFormat.JPEG,+70,+stream);
++++++++byte[]+byteFormat+=+stream.toByteArray();

++++++++//+Get+the+Base64+string
++++++++String+imgString+=+Base64.encodeToString(byteFormat,+Base64.NO_WRAP);

++++++++return+imgString;
++++}

++++@Override
++++protected+void+onPostExecute(String+s)+{
+++++++textView5.setText(s);
++++}
}.execute();|807752|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Here is code for image encoding and image decoding.

In an XML file

<pre><code>&lt;TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="yyuyuyuuyuyuyu"
 android:id="@+id/tv5"
/&gt;
</code></pre>

In a Java file:

<pre><code>TextView textView5;
Bitmap bitmap;

textView5 = (TextView) findViewById(R.id.tv5);

bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.logo);

new AsyncTask&lt;Void, Void, String&gt;() {
 @Override
 protected String doInBackground(Void... voids) {
 ByteArrayOutputStream stream = new ByteArrayOutputStream();
 bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream);
 byte[] byteFormat = stream.toByteArray();

 // Get the Base64 string
 String imgString = Base64.encodeToString(byteFormat, Base64.NO_WRAP);

 return imgString;
 }

 @Override
 protected void onPostExecute(String s) {
 textView5.setText(s);
 }
}.execute();
</code></pre>

blocks|key|1022522|text|我做了一个静态函数。我认为这样更有效率。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1022523|public+static+String+file2Base64(String+filePath)+{
++++++++FileInputStream+fis+=+null;
++++++++String+base64String+=+"";
++++++++ByteArrayOutputStream+bos+=+new+ByteArrayOutputStream();
++++++++try+{
++++++++++++fis+=+new+FileInputStream(filePath);
++++++++++++byte[]+buffer+=+new+byte[1024+*+100];
++++++++++++int+count+=+0;
++++++++++++while+((count+=+fis.read(buffer))+!=+-1)+{
++++++++++++++++bos.write(buffer,+0,+count);
++++++++++++}
++++++++++++fis.close();
++++++++}+catch+(Exception+e)+{
++++++++++++e.printStackTrace();
++++++++}
++++++++base64String+=+Base64.encodeToString(bos.toByteArray(),+Base64.DEFAULT);
++++++++return+base64String;

++++}|code-block|syntax|javascript|1022524|简单，更容易！|1022525|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I make a static function. Its more efficient i think.
<pre><code>public static String file2Base64(String filePath) {
 FileInputStream fis = null;
 String base64String = &quot;&quot;;
 ByteArrayOutputStream bos = new ByteArrayOutputStream();
 try {
 fis = new FileInputStream(filePath);
 byte[] buffer = new byte[1024 * 100];
 int count = 0;
 while ((count = fis.read(buffer)) != -1) {
 bos.write(buffer, 0, count);
 }
 fis.close();
 } catch (Exception e) {
 e.printStackTrace();
 }
 base64String = Base64.encodeToString(bos.toByteArray(), Base64.DEFAULT);
 return base64String;

 }
</code></pre>
Simple and easier!

blocks|key|1022537|text|Kotlin版本：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1022538|fun+File.toBase64():+String?+{
+val+result:+String?
+inputStream().use+{+inputStream+->
++++val+sourceBytes+=+inputStream.readBytes()
++++result+=+Base64.encodeToString(sourceBytes,+Base64.DEFAULT)
+}

+return+result
}|code-block|syntax|javascript|1022539|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|$]]

Kotlin version:
<pre><code>fun File.toBase64(): String? {
 val result: String?
 inputStream().use { inputStream -&gt;
 val sourceBytes = inputStream.readBytes()
 result = Base64.encodeToString(sourceBytes, Base64.DEFAULT)
 }

 return result
}
</code></pre>

What is the code to transform an image (maximum of 200&nbsp;KB) into a Base64 String?

I need to know how to do it with Android, because I have to add the functionality to upload images to a remote server in my main app, putting them into a row of the database, as a string.

I am searching in Google and in Stack Overflow, but I could not find easy examples that I can afford and also I find some examples, but they are not talking about to transform into a String. Then I need to transform into a string to upload by JSON to my remote server.

How can I convert an image into a Base64 string?

将图片(最大200kb)转换为Base64字符串的代码是什么？我需要知道如何在Android中做到这一点，因为我必须在我的主应用程序中添加上传图像到远程服务器的功能，将它们作为字符串放入数据库的一行中。我在Google和Stack Overflow中搜索，但我找不到我能负担得起的简单示例，我也找到了一些示例，但它们不是...

问如何将图片转换为Base64字符串？
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问如何将图片转换为Base64字符串？
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