blocks|key|51954|text|这段Java代码读取每个单词并将其放入ArrayList:|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|51955|Scanner+s+=+new+Scanner(new+File("filepath"));
ArrayList<String>+list+=+new+ArrayList<String>();
while+(s.hasNext()){
++++list.add(s.next());
}
s.close();|code-block|syntax|javascript|51956|如果要逐行阅读而不是逐字阅读，请使用s.hasNextLine()和s.nextLine()。|CODE|51957|entityMap^0|0|T|0|0|I|F|Y|C|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|S|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|T|8|@$9|U|A|V|B|M]|$9|W|A|X|B|M]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|O|$]]

This Java code reads in each word and puts it into the ArrayList:

<pre><code>Scanner s = new Scanner(new File("filepath"));
ArrayList&lt;String&gt; list = new ArrayList&lt;String&gt;();
while (s.hasNext()){
 list.add(s.next());
}
s.close();
</code></pre>

Use <code>s.hasNextLine()</code> and <code>s.nextLine()</code> if you want to read in line by line instead of word by word.

blocks|key|51105|text|您可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|51106|List<String>+list+=+Files.readAllLines(new+File("input.txt").toPath(),+Charset.defaultCharset()+);|code-block|syntax|javascript|51107|来源：Java+API+7.0|offset|length|51108|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html#readAllLines%2528java.nio.file.Path,%2520java.nio.charset.Charset%2529^0|0|0|3|C|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

You can use:

<pre><code>List&lt;String&gt; list = Files.readAllLines(new File("input.txt").toPath(), Charset.defaultCharset() );
</code></pre>

Source: <a href="http://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html#readAllLines%28java.nio.file.Path,%20java.nio.charset.Charset%29">Java API 7.0</a>

blocks|key|51347|text|commons-io的一行代码|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|51348|List<String>+lines+=+FileUtils.readLines(new+File("/path/to/file.txt"),+"utf-8");|code-block|syntax|javascript|51349|guava也是如此|51350|List<String>+lines+=+
+++++Files.readLines(new+File("/path/to/file.txt"),+Charset.forName("utf-8"));|51351|entityMap|0|LINK|mutability|MUTABLE|url|http://commons.apache.org/io/|1|https://code.google.com/p/guava-libraries/^0|0|A|0|0|0|0|5|1|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@$A|12|B|13|1|14]]|C|$]]|$1|K|3|L|5|F|7|15|8|@]|9|@]|C|$G|H]]|$1|M|3|-4|5|6|7|16|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]|U|$5|P|Q|R|C|$S|V]]]]

A one-liner with <a href="http://commons.apache.org/io/" rel="noreferrer">commons-io</a>:

<pre><code>List&lt;String&gt; lines = FileUtils.readLines(new File("/path/to/file.txt"), "utf-8");
</code></pre>

The same with <a href="https://code.google.com/p/guava-libraries/" rel="noreferrer">guava</a>:

<pre><code>List&lt;String&gt; lines = 
 Files.readLines(new File("/path/to/file.txt"), Charset.forName("utf-8"));
</code></pre>

blocks|key|2743663|text|我找到的最简单的形式是...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2743664|List<String>+lines+=+Files.readAllLines(Paths.get("/path/to/file.txt"));|code-block|syntax|javascript|2743665|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|$]]

Simplest form I ever found is...

<pre><code>List&lt;String&gt; lines = Files.readAllLines(Paths.get("/path/to/file.txt"));
</code></pre>

blocks|key|2743616|text|在Java8中，可以使用streams和Files.lines|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|CODE|entityRanges|data|2743617|List<String>+list+=+null;
try+(Stream<String>+lines+=+Files.lines(myPathToTheFile)))+{
++++list+=+lines.collect(Collectors.toList());
}+catch+(IOException+e)+{
++++LOGGER.error("Failed+to+load+file.",+e);
}|code-block|syntax|javascript|2743618|或者作为包括从文件系统加载文件的功能：|2743619|private+List<String>+loadFile()+{
++++List<String>+list+=+null;
++++URI+uri+=+null;

++++try+{
++++++++uri+=+ClassLoader.getSystemResource("example.txt").toURI();
++++}+catch+(URISyntaxException+e)+{
++++++++LOGGER.error("Failed+to+load+file.",+e);
++++}

++++try+(Stream<String>+lines+=+Files.lines(Paths.get(uri)))+{
++++++++list+=+lines.collect(Collectors.toList());
++++}+catch+(IOException+e)+{
++++++++LOGGER.error("Failed+to+load+file.",+e);
++++}
++++return+list;
}|2743620|entityMap^0|1|5|K|B|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]|$9|U|A|V|B|D]]|E|@]|F|$]]|$1|G|3|H|5|I|7|W|8|@]|E|@]|F|$J|K]]|$1|L|3|M|5|6|7|X|8|@]|E|@]|F|$]]|$1|N|3|O|5|I|7|Y|8|@]|E|@]|F|$J|K]]|$1|P|3|-4|5|6|7|Z|8|@]|E|@]|F|$]]]|Q|$]]

In Java 8 you could use streams and <code>Files.lines</code>:

<pre><code>List&lt;String&gt; list = null;
try (Stream&lt;String&gt; lines = Files.lines(myPathToTheFile))) {
 list = lines.collect(Collectors.toList());
} catch (IOException e) {
 LOGGER.error("Failed to load file.", e);
}
</code></pre>

Or as a function including loading the file from the file system:

<pre><code>private List&lt;String&gt; loadFile() {
 List&lt;String&gt; list = null;
 URI uri = null;

 try {
 uri = ClassLoader.getSystemResource("example.txt").toURI();
 } catch (URISyntaxException e) {
 LOGGER.error("Failed to load file.", e);
 }

 try (Stream&lt;String&gt; lines = Files.lines(Paths.get(uri))) {
 list = lines.collect(Collectors.toList());
 } catch (IOException e) {
 LOGGER.error("Failed to load file.", e);
 }
 return list;
}
</code></pre>

blocks|key|51947|text|List<String>+words+=+new+ArrayList<String>();
BufferedReader+reader+=+new+BufferedReader(new+FileReader("words.txt"));
String+line;
while+((line+=+reader.readLine())+!=+null)+{
++++words.add(line);
}
reader.close();|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|51948|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>List&lt;String&gt; words = new ArrayList&lt;String&gt;();
BufferedReader reader = new BufferedReader(new FileReader("words.txt"));
String line;
while ((line = reader.readLine()) != null) {
 words.add(line);
}
reader.close();
</code></pre>

blocks|key|2743543|text|例如，你可以这样做(完整的代码和异常handlig)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2743544|BufferedReader+in+=+null;
List<String>+myList+=+new+ArrayList<String>();
try+{+++
++++in+=+new+BufferedReader(new+FileReader("myfile.txt"));
++++String+str;
++++while+((str+=+in.readLine())+!=+null)+{
++++++++myList.add(str);
++++}
}+catch+(FileNotFoundException+e)+{
++++e.printStackTrace();
}+catch+(IOException+e)+{
++++e.printStackTrace();
}+finally+{
++++if+(in+!=+null)+{
++++++++in.close();
++++}
}|code-block|syntax|javascript|2743545|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|$]]

You can for example do this in this way (full code with exceptions handlig):

<pre><code>BufferedReader in = null;
List&lt;String&gt; myList = new ArrayList&lt;String&gt;();
try { 
 in = new BufferedReader(new FileReader("myfile.txt"));
 String str;
 while ((str = in.readLine()) != null) {
 myList.add(str);
 }
} catch (FileNotFoundException e) {
 e.printStackTrace();
} catch (IOException e) {
 e.printStackTrace();
} finally {
 if (in != null) {
 in.close();
 }
}
</code></pre>

blocks|key|2743586|text|//CS124+HW6+Wikipedia+Relation+Extraction
//Alan+Joyce+(ajoyce)
public+List<String>+addWives(String+fileName)+{
++++List<String>+wives+=+new+ArrayList<String>();
++++try+{
++++++++BufferedReader+input+=+new+BufferedReader(new+FileReader(fileName));
++++++++//+for+each+line
++++++++for(String+line+=+input.readLine();+line+!=+null;+line+=+input.readLine())+{
++++++++++++wives.add(line);
++++++++}
++++++++input.close();
++++}+catch(IOException+e)+{
++++++++e.printStackTrace();
++++++++System.exit(1);
++++++++return+null;
++++}
++++return+wives;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2743587|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>//CS124 HW6 Wikipedia Relation Extraction
//Alan Joyce (ajoyce)
public List&lt;String&gt; addWives(String fileName) {
 List&lt;String&gt; wives = new ArrayList&lt;String&gt;();
 try {
 BufferedReader input = new BufferedReader(new FileReader(fileName));
 // for each line
 for(String line = input.readLine(); line != null; line = input.readLine()) {
 wives.add(line);
 }
 input.close();
 } catch(IOException e) {
 e.printStackTrace();
 System.exit(1);
 return null;
 }
 return wives;
}
</code></pre>

blocks|key|2533851|text|这是一个对我来说效果很好的解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2533852|List<String>+lines+=+Arrays.asList(
++++new+Scanner(new+File(file)).useDelimiter("\\Z").next().split("\\r?\\n")
);|code-block|syntax|javascript|2533853|如果你不想要空行，你也可以这样做：|2533854|List<String>+lines+=+Arrays.asList(
++++new+Scanner(new+File(file)).useDelimiter("\\Z").next().split("[\\r\\n]%2B")
);|2533855|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Here's a solution that has worked pretty well for me:

<pre><code>List&lt;String&gt; lines = Arrays.asList(
 new Scanner(new File(file)).useDelimiter("\\Z").next().split("\\r?\\n")
);
</code></pre>

If you don't want empty lines, you can also do:

<pre><code>List&lt;String&gt; lines = Arrays.asList(
 new Scanner(new File(file)).useDelimiter("\\Z").next().split("[\\r\\n]+")
);
</code></pre>

blocks|key|51158|text|分享一些分析信息。通过一个简单的测试，读取~1180行值需要多长时间。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|51159|如果您需要非常快地读取数据，请使用很好的旧BufferedReader+FileReader示例。我花了大约8毫秒|51160|扫描仪的速度要慢得多。我花了大约138毫秒|51161|漂亮的Java8+Files.lines(...)是最慢的版本。我花了大约388毫秒。|51162|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

To share some analysis info. With a simple test how long it takes to read ~1180 lines of values.

If you need to read the data very fast, use the good old BufferedReader FileReader example. It took me ~8ms

The Scanner is much slower. Took me ~138ms

The nice Java 8 Files.lines(...) is the slowest version. Took me ~388ms.

blocks|key|2743567|text|下面是一个完整的程序示例：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2743568|import+java.io.File;
import+java.io.FileNotFoundException;
import+java.util.ArrayList;
import+java.util.Scanner;

public+class+X+{
++++public+static+void+main(String[]+args)+{
++++File+f+=+new+File("D:/projects/eric/eclipseworkspace/testing2/usernames.txt");
++++++++try{
++++++++++++ArrayList<String>+lines+=+get_arraylist_from_file(f);
++++++++++++for(int+x+=+0;+x+<+lines.size();+x%2B%2B){
++++++++++++++++System.out.println(lines.get(x));
++++++++++++}
++++++++}
++++++++catch(Exception+e){
++++++++++++e.printStackTrace();
++++++++}
++++++++System.out.println("done");

++++}
++++public+static+ArrayList<String>+get_arraylist_from_file(File+f)+
++++++++throws+FileNotFoundException+{
++++++++Scanner+s;
++++++++ArrayList<String>+list+=+new+ArrayList<String>();
++++++++s+=+new+Scanner(f);
++++++++while+(s.hasNext())+{
++++++++++++list.add(s.next());
++++++++}
++++++++s.close();
++++++++return+list;
++++}
}|code-block|syntax|javascript|2743569|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 an entire program example:

<pre><code>import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;

public class X {
 public static void main(String[] args) {
 File f = new File("D:/projects/eric/eclipseworkspace/testing2/usernames.txt");
 try{
 ArrayList&lt;String&gt; lines = get_arraylist_from_file(f);
 for(int x = 0; x &lt; lines.size(); x++){
 System.out.println(lines.get(x));
 }
 }
 catch(Exception e){
 e.printStackTrace();
 }
 System.out.println("done");

 }
 public static ArrayList&lt;String&gt; get_arraylist_from_file(File f) 
 throws FileNotFoundException {
 Scanner s;
 ArrayList&lt;String&gt; list = new ArrayList&lt;String&gt;();
 s = new Scanner(f);
 while (s.hasNext()) {
 list.add(s.next());
 }
 s.close();
 return list;
 }
}
</code></pre>

blocks|key|2743718|text|++++Scanner+scr+=+new+Scanner(new+File(filePathInString));
/*Above+line+for+scanning+data+from+file*/

++++enter+code+here

ArrayList<DataType>+list+=+new+ArrayList<DateType>();
/*this+is+a+object+of+arraylist+which+in+data+will+store+after+scan*/

while+(scr.hasNext()){|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2743719|list.add(scr.next())；}借助add函数，/*above代码负责将数据添加到数组列表中*/|unstyled|2743720|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code> Scanner scr = new Scanner(new File(filePathInString));
/*Above line for scanning data from file*/

 enter code here

ArrayList&lt;DataType&gt; list = new ArrayList&lt;DateType&gt;();
/*this is a object of arraylist which in data will store after scan*/

while (scr.hasNext()){
</code></pre>

list.add(scr.next());
}
/*above code is responsible for adding data in arraylist with the help of add function */

blocks|key|50716|text|添加此代码以对文本文件中的数据进行排序。Collections.sort(list);|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|50717|entityMap^0|K|N|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

Add this code to sort the data in text file.
<code>Collections.sort(list);</code>

How do you read the contents of a file into an <code>ArrayList&lt;String&gt;</code> in Java? 

Here are the file contents:

<pre><code>cat
house
dog
.
.
.
</code></pre>

Just read each word into the <code>ArrayList</code>.

Java reading a file into an ArrayList?

文件系统

Java

在Java语言中，如何将文件内容读入ArrayList<String>？以下是文件内容：cathousedog...只需将每个单词读入ArrayList即可。

问Java将文件读入ArrayList？
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回答 13

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