java 对txt文件读写（已经封装好）

读文件：

 1 public static String readTxt(String txtPath) {
 2         File file = new File(txtPath);
 3         if(file.isFile() && file.exists()){
 4             try {
 5                 FileInputStream fileInputStream = new FileInputStream(file);
 6                 InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
 7                 BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
 8                  
 9                 StringBuffer sb = new StringBuffer();
10                 String text = null;
11                 while((text = bufferedReader.readLine()) != null){
12                     sb.append(text);
13                 }
14                 return sb.toString();
15             } catch (Exception e) {
16                 e.printStackTrace();
17             }
18         }
19         return null;
20     }

写文件：

 1  public static void writeTxt(String txtPath,String content){    
 2            FileOutputStream fileOutputStream = null;
 3            File file = new File(txtPath);
 4            try {
 5                if(file.exists()){
 6                    //判断文件是否存在，如果不存在就新建一个txt
 7                    file.createNewFile();
 8                }
 9                fileOutputStream = new FileOutputStream(file,true);//多个true就是追加
10                fileOutputStream.write(content.getBytes());
11                fileOutputStream.flush();
12                fileOutputStream.close();
13            } catch (Exception e) {
14                e.printStackTrace();
15            }
16         }

完整代码：

 1 import java.io.BufferedReader;
 2 import java.io.File;
 3 import java.io.FileInputStream;
 4 import java.io.FileOutputStream;
 5 import java.io.InputStreamReader;
 6 public class 文件读写 {
 7 public static String readTxt(String txtPath) {
 8         File file = new File(txtPath);
 9         if(file.isFile() && file.exists()){
10             try {
11                 FileInputStream fileInputStream = new FileInputStream(file);
12                 InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
13                 BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
14                  
15                 StringBuffer sb = new StringBuffer();
16                 String text = null;
17                 while((text = bufferedReader.readLine()) != null){
18                     sb.append(text);
19                 }
20                 return sb.toString();
21             } catch (Exception e) {
22                 e.printStackTrace();
23             }
24         }
25         return null;
26     }
27      public static void writeTxt(String txtPath,String content){    
28            FileOutputStream fileOutputStream = null;
29            File file = new File(txtPath);
30            try {
31                if(file.exists()){
32                    //判断文件是否存在，如果不存在就新建一个txt
33                    file.createNewFile();
34                }
35                fileOutputStream = new FileOutputStream(file,true);//多个true就是追加
36                fileOutputStream.write(content.getBytes());
37                fileOutputStream.flush();
38                fileOutputStream.close();
39            } catch (Exception e) {
40                e.printStackTrace();
41            }
42         }
43 }