io流之写文件

 1 package book.io;
 2 
 3 import java.io.File;
 4 import java.io.FileNotFoundException;
 5 import java.io.FileOutputStream;
 6 import java.io.IOException;
 7 import java.io.OutputStream;
 8 import java.io.OutputStreamWriter;
 9 import java.io.PrintWriter;
10 import java.io.Writer;
11 
12 public class WriteToFile {
13     //以字节为单位写文件，适合于写二进制文件，如图片等
14     public static void writeFileByBytes(String fileName){
15         File file = new File(fileName);
16         OutputStream out = null;
17         try {
18             out = new FileOutputStream(file);
19             String content = "文件内容：\n1,The First line;\n2,The Second line";
20             byte[] bytes = content.getBytes();//读取文件输出流中的字节
21             //写入文件
22             out.write(bytes);
23             System.out.println("写文件" + file.getAbsolutePath() + "成功！");
24         } catch (IOException e) {
25             System.out.println("写文件" + file.getAbsolutePath() + "失败！");
26             e.printStackTrace();
27         }finally{
28             if(out != null){
29                 try {
30                     out.close();
31                 } catch (IOException e) {
32                     e.printStackTrace();
33                 }
34             }
35         }
36     }
37     //以字符为单位写文件
38     public static void writeFileByChars(String fileName){
39         File file = new File(fileName);
40         Writer writer = null;
41         try {
42             writer = new OutputStreamWriter(new FileOutputStream(file));
43             String content = "文件内容：\n1,The first line;\n2,The second line";
44             writer.write(content);
45             System.out.println("写文件" + file.getAbsolutePath() + "成功！");
46         } catch (IOException e) {
47             System.out.println("写文件" + file.getAbsolutePath() + "失败！");
48             e.printStackTrace();
49         }finally{
50             if(writer != null){
51                 try {
52                     writer.close();
53                 } catch (IOException e) {
54                     e.printStackTrace();
55                 }
56             }
57         }
58     }
59     //以行为单位写文件
60     public static void writeFileByLines(String fileName){
61         File file = new File(fileName);
62         PrintWriter writer = null;
63         try {
64             writer = new PrintWriter(new FileOutputStream(file));
65             writer.println("文件内容：");
66             //写入各种基本类型数据
67             writer.println(true);
68             writer.print(155);
69             writer.println();
70             writer.flush();
71             System.out.println("写文件" + file.getAbsolutePath() + "成功！");
72         } catch (FileNotFoundException e) {
73             System.out.println("写文件" + file.getAbsolutePath() + "失败！");
74             e.printStackTrace();
75         }finally{
76             if(writer != null){
77                 writer.close();
78             }
79         }
80     }
81     public static void main(String[] args){
82         String fileName = "C:/Users/Admin/Desktop/CAI/20160720/temp1.txt";
83         WriteToFile.writeFileByBytes(fileName);
84         fileName = "C:/Users/Admin/Desktop/CAI/20160720/temp2.txt";
85         WriteToFile.writeFileByChars(fileName);
86         fileName = "C:/Users/Admin/Desktop/CAI/20160720/temp3.txt";
87         WriteToFile.writeFileByLines(fileName);
88     }
89 }