自定义注解

@Taget({ElementType.METHOD, ElementType.TYPE})

    CONSTRUCTOR 构造方法
    FIELD 字段声明

    LOCAL_VARIABLE 局部变量

    METHOD 方法声明

    PACKAGE 包声明

    PARAMENTER 参数声明

    TYPE 类或接口

@Retention(RetentionPolicy.RUNTIME)

    SOURCE 只在源码显示，编译时会丢弃

    CLASS 编译时会记录到class中，运行时忽略

    RUNTIME 运行时存在，可以通过反射读取

@Inherited

    允许自雷继承

@Documented

    生成javadoc时会包含注解

/**
 * Description: ToStringIgnore
 * 这个方法表示ToString方法忽略该字段
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.FIELD })
@Documented
public @interface ToStringIgnore {

}

public class ToStringUtils {

    private static Joiner joiner = Joiner.on(", \n");

    public static String toString(Object o) {
        String str = o.getClass().getSimpleName() + " { \n";
        Field[] declaredFields = o.getClass().getDeclaredFields();
        List<String> fields = Lists.newArrayList();
        if (declaredFields != null && declaredFields.length != 0) {
            for (Field item : declaredFields) {
                if (null != item.getAnnotation(ToStringIgnore.class)) {
                    continue;
                }
                item.setAccessible(true);
                String field = "";
                try {
                    field = item.getName() + ":" + item.get(o);
                } catch (IllegalAccessException ignore) {}
                fields.add(field);
            }
        }
        str += joiner.join(fields) + " \n} ";
        return str;
    }
}

public class User implements Serializable {

    private static final long serialVersionUID = -5334408912188522583L;

    private int id;

    private String username;

    @ToStringIgnore
    private String password;

    private String firstName;

    private int age;

    private boolean male;

    public User(int id, String username, String password, String firstName, int age, boolean male) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.firstName = firstName;
        this.age = age;
        this.male = male;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public int getAge() {
        return age;
    }

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

    public boolean isMale() {
        return male;
    }

    public void setMale(boolean male) {
        this.male = male;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", firstName='" + firstName + '\'' +
                ", age=" + age +
                ", male=" + male +
                '}';
    }
}

    @Test
    public void test() {
        String s = ToStringUtils.toString(new User(1, "admin", "admin", "asldas", 1, true));
        logger.info("{}", s);
    }