Merge pull request giantray#27 from andyfeng101/master

新增“在java中如何创建文件和写文件”

Author: giantray

contents/get-current-stack-trace-in-java.md

@@ -8,5 +8,9 @@
 String fullStackTrace = org.apache.commons.lang.exception.ExceptionUtils.getFullStackTrace(e)
 ```
 
+````java
+Thread.currentThread().getStackTrace();
+````
+
 stackoverflow原址：
 http://stackoverflow.com/questions/1069066/how-can-i-get-the-current-stack-trace

contents/how-to-create-a-file-and-write-to-a-file-in-java.md

@@ -0,0 +1,149 @@
+## 用java怎么样创建一个文件并向该文件写文本内容
+
+### 问：在java里最简单的创建文件写文件的方法是什么
+
+### 最佳答案:
+创建一个文本文件（注意：如果该文件存在，则会覆盖该文件）
+````java
+PrintWriter writer = new PrintWriter("the-file-name.txt", "UTF-8");
+writer.println("The first line");
+writer.println("The second line");
+writer.close();
+````
+创建一个位二进制文件（同样会覆盖这文件）
+````java
+byte data[] = ...
+FileOutputStream out = new FileOutputStream("the-file-name");
+out.write(data);
+out.close();
+````
+
+Java 7+ 用户可以用[`File`](http://docs.oracle.com/javase/7/docs/api/index.html?java/nio/file/Files.html)类来写文件
+创建一个文本文件
+````java
+List<String> lines = Arrays.asList("The first line", "The second line");
+Path file = Paths.get("the-file-name.txt");
+Files.write(file, lines, Charset.forName("UTF-8"));
+//Files.write(file, lines, Charset.forName("UTF-8"), StandardOpenOption.APPEND);
+````
+创建一个二进制文件
+````java
+byte data[] = ...
+Path file = Paths.get("the-file-name");
+Files.write(file, data);
+//Files.write(file, data, StandardOpenOption.APPEND);
+````
+
+### 其他的答案（1）:
+在Java 7+中
+````java
+try (Writer writer = new BufferedWriter(new OutputStreamWriter(
+              new FileOutputStream("filename.txt"), "utf-8"))) {
+   writer.write("something");
+}
+````
+还有一些实用的方法如下：
+* [`FileUtils.writeStringtoFile(..)`](https://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/FileUtils.html#writeStringToFile%28java.io.File,%20java.lang.String,%20java.nio.charset.Charset%29) 来自于 commons-io 包
+* [`Files.write(..)`](http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/io/Files.html#write%28java.lang.CharSequence,%20java.io.File,%20java.nio.charset.Charset%29) 来自于 guava
+Note also that you can use a FileWriter, but it uses the default encoding, 
+which is often a bad idea - it's best to specify the encoding explicitly.
+还要注意可以使用 `FileWriter`，但是它使用的是默认编码，这不是很好的方法，最好是明确指定编码
+
+
+下面是来自于prior-to-java-7的原始方法
+````java
+Writer writer = null;
+
+try {
+    writer = new BufferedWriter(new OutputStreamWriter(
+          new FileOutputStream("filename.txt"), "utf-8"));
+    writer.write("Something");
+} catch (IOException ex) {
+  // report
+} finally {
+   try {writer.close();} catch (Exception ex) {/*ignore*/}
+}
+````
+可以看[`Reading, Writing, and Creating Files`](http://docs.oracle.com/javase/tutorial/essential/io/file.html)(包含NIO2)
+
+### 其他答案（2）：
+````java
+public class Program {
+    public static void main(String[] args) {
+        String text = "Hello world";
+        BufferedWriter output = null;
+        try {
+            File file = new File("example.txt");
+            output = new BufferedWriter(new FileWriter(file));
+            output.write(text);
+        } catch ( IOException e ) {
+            e.printStackTrace();
+        } finally {
+            if ( output != null ) output.close();
+        }
+    }
+}
+````
+
+### 其他答案（3）：
+如果已经有想要写到文件中的内容，[`java.nio.file.Files`](https://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html) 作为 Java 7 附加部分的native I/O，提供了简单高效的方法来实现你的目标
+
+基本上创建文件，写文件只需要一行，而且是只需一个方法调用！
+下面的例子创建并且写了6个不同的文件来展示是怎么使用的
+
+````java
+Charset utf8 = StandardCharsets.UTF_8;
+List<String> lines = Arrays.asList("1st line", "2nd line");
+byte[] data = {1, 2, 3, 4, 5};
+
+try {
+    Files.write(Paths.get("file1.bin"), data);
+    Files.write(Paths.get("file2.bin"), data,
+            StandardOpenOption.CREATE, StandardOpenOption.APPEND);
+    Files.write(Paths.get("file3.txt"), "content".getBytes());
+    Files.write(Paths.get("file4.txt"), "content".getBytes(utf8));
+    Files.write(Paths.get("file5.txt"), lines, utf8);
+    Files.write(Paths.get("file6.txt"), lines, utf8,
+            StandardOpenOption.CREATE, StandardOpenOption.APPEND);
+} catch (IOException e) {
+    e.printStackTrace();
+}
+````
+
+### 其他答案（4）：
+下面是一个小程序来创建和写文件。该版本的代码比较长，但是可以容易理解
+````java
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+
+public class writer {
+    public void writing() {
+        try {
+            //Whatever the file path is.
+            File statText = new File("E:/Java/Reference/bin/images/statsTest.txt");
+            FileOutputStream is = new FileOutputStream(statText);
+            OutputStreamWriter osw = new OutputStreamWriter(is);    
+            Writer w = new BufferedWriter(osw);
+            w.write("POTATO!!!");
+            w.close();
+        } catch (IOException e) {
+            System.err.println("Problem writing to the file statsTest.txt");
+        }
+    }
+
+    public static void main(String[]args) {
+        writer write = new writer();
+        write.writing();
+    }
+}
+````
+
+
+
+
+stackoverflow链接：
+http://stackoverflow.com/questions/2885173/how-to-create-a-file-and-write-to-a-file-in-java