1. 单元测试Junit

1.1 什么是单元测试？（掌握）

1.2 Junit的特点？（掌握）

1.3 基本用法：（掌握）

实际开发中单元测试的使用方式（掌握）

public class TestDemo {
    public int addMethod(int a,int b){
        return a+b;
    }
}

public class Main {
    @Test
    public void method(){
        TestDemo testDemo = new TestDemo();
        int result = testDemo.addMethod(3, 4);

        Assert.assertEquals("add方法错了",result,7);
    }
}

public class Main {
@Before
public void beforeMethod() throws IOException {
//先备份
File src = new File("a.txt");
File dest = new File("b.txt");
FileInputStream fis = new FileInputStream(src);
FileOutputStream fos = new FileOutputStream(dest);
int b;
while ((b=fis.read())!=-1){
fos.write(b);
}
fos.close();
fis.close();
}
@Test
public void testMethod(){
File file = new File("a.txt");
//删除文件
boolean result = file.delete();
//文件是否存在
boolean exists = file.exists();
//只有同时满足了，才表示delete方法正确
Assert.assertEquals("delete方法错了",result,true);
Assert.assertEquals("delete方法错了",exists,false);
}
@After
public void afterMethod() throws IOException {
//还原数据
File dest = new File("a.txt");
File src = new File("b.txt");
FileInputStream fis = new FileInputStream(src);
FileOutputStream fos = new FileOutputStream(dest);
int b;
while ((b=fis.read())!=-1){
fos.write(b);
}
fos.close();
fis.close();
//删除备份数据
src.delete();
}
}