1 import static org.junit.Assert.*; 2  3 import java.io.File; 4 import java.io.FileWriter; 5 import java.io.IOException; 6  7 import org.junit.Test; 8  9 10 11 public class MyTest {12     //通过字符流写入数据到指定的文件中13     @Test14     public void testWrite() {15         String path = "F:"+File.separator+"demo.txt";16 //        如果文件不存在的话，就先创建这个文件17         File file = new File(path);18         if(!file.exists()){19             try {20                 file.createNewFile();21             } catch (IOException e) {22                 // TODO Auto-generated catch block23                 e.printStackTrace();24             }25         }26         FileWriter fileWriter = null;27         try {28             //在Windows中，一定要确保路径为path的文件是存在的29             fileWriter = new FileWriter(path);30             fileWriter.write("you are not a good boy!");31             fileWriter.flush();32             fileWriter.close();33         } catch (IOException e) {34             // TODO Auto-generated catch block35             e.printStackTrace();36         }finally{37             //如果抛出异常的话，说明fileWriter对象时候创建不了的38             if(fileWriter!=null){39                 try {40                     fileWriter.close();41                 } catch (IOException e) {42                     // TODO Auto-generated catch block43                     e.printStackTrace();44                 }45             }46             47         }48         49         50     }51 52 }