lombok的使用

1、@NonNull  非空检验可以用@notNull代替，后者还可以有返回信息

@NotNull(message = "参数不能为null")
    private boolean name;
    @NonNull
    private int age;

2、@Cleanup---这个在jdk1.7之后，可以用try with resourse

释放资源

public void test(){
        try {
            @Cleanup OutputStream outputStream = new FileOutputStream("");
            outputStream.write(5);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

反编译后

public void test() {
        try {
            FileOutputStream e = new FileOutputStream("");

            try {
                e.write(5);
            } finally {
                if(Collections.singletonList(e).get(0) != null) {
                    e.close();
                }

            }
        } catch (Exception var6) {
            var6.printStackTrace();
        }

    }

try-with-resourse

public void test(){
        try (OutputStream outputStream = new FileOutputStream("")){
            outputStream.write(5);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

反编译后

public void test() {
        try {
            FileOutputStream e = new FileOutputStream("");
            Throwable var2 = null;

            try {
                e.write(5);
            } catch (Throwable var12) {
                var2 = var12;
                throw var12;
            } finally {
                if(e != null) {
                    if(var2 != null) {
                        try {
                            e.close();
                        } catch (Throwable var11) {
                            var2.addSuppressed(var11);
                        }
                    } else {
                        e.close();
                    }
                }

            }
        } catch (Exception var14) {
            var14.printStackTrace();
        }

    }

3、@getter--@setter---@Accessors

chain属性，可以想jq一样连续编程(默认是false)

@Getter
@Setter
@Accessors(chain = true)
public class TestDTO {

    private String name;

    private int age;

}

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String getName() {
        return this.name;
    }

    public int getAge() {
        return this.age;
    }

    public TestDTO setName(String name) {
        this.name = name;
        return this;
    }

    public TestDTO setAge(int age) {
        this.age = age;
        return this;
    }
}

4、@ToString

@ToString
public class TestDTO {

    private String name;

    private int age;

}

反编译

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(name=" + this.name + ", age=" + this.age + ")";
    }
}

ToString里面的属性 includeFieldNames = false

@ToString(includeFieldNames = false)
public class TestDTO {

    private String name;

    private int age;

}

反编译后--没有字段的名称

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(" + this.name + ", " + this.age + ")";
    }
}

第二个属性

@ToString(exclude = "age")
public class TestDTO {

    private String name;

    private int age;

}

反编译后--排除了exclude指定的属性

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(name=" + this.name + ")";
    }
}

第三个属性

@ToString(of = "age")
public class TestDTO {

    private String name;

    private int age;

}

反编译后--只出现了of = "age" 中的属性

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(age=" + this.age + ")";
    }
}

第四个属性

@ToString(callSuper =true )
public class TestDTO {

    private String name;

    private int age;

}

反编译后--输出了父类的toString

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(super=" + super.toString() + ", name=" + this.name + ", age=" + this.age + ")";
    }
}

第五个属性

@ToString
@Getter
public class TestDTO {

    private String name;

    private int age;

}

反编译后--使用了有@getter注解后使用了get方法

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(name=" + this.getName() + ", age=" + this.getAge() + ")";
    }

    public String getName() {
        return this.name;
    }

    public int getAge() {
        return this.age;
    }
}

使用属性

@ToString(doNotUseGetters = true)
@Getter
public class TestDTO {

    private String name;

    private int age;

}

反编译后---  (doNotUseGetters = true)--没有使用get方法，而是直接使用this.属性

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public String toString() {
        return "TestDTO(name=" + this.name + ", age=" + this.age + ")";
    }

    public String getName() {
        return this.name;
    }

    public int getAge() {
        return this.age;
    }
}

5、@EqualsAndHashCode

@EqualsAndHashCode
public class TestDTO {

    private String name;

    private int age;

}

反编译后

public class TestDTO {
    private String name;
    private int age;

    public TestDTO() {
    }

    public boolean equals(Object o) {
        if(o == this) {
            return true;
        } else if(!(o instanceof TestDTO)) {
            return false;
        } else {
            TestDTO other = (TestDTO)o;
            if(!other.canEqual(this)) {
                return false;
            } else {
                String this$name = this.name;
                String other$name = other.name;
                if(this$name == null) {
                    if(other$name == null) {
                        return this.age == other.age;
                    }
                } else if(this$name.equals(other$name)) {
                    return this.age == other.age;
                }

                return false;
            }
        }
    }

    protected boolean canEqual(Object other) {
        return other instanceof TestDTO;
    }

    public int hashCode() {
        boolean PRIME = true;
        byte result = 1;
        String $name = this.name;
        int result1 = result * 59 + ($name == null?43:$name.hashCode());
        result1 = result1 * 59 + this.age;
        return result1;
    }
}