Lombok

Project Lombok is a java library that automatically plugs into your editor and build tools, spicing up your java.
Never write another getter or equals method again, with one annotation your class has a fully featured builder, Automate your logging variables, and much more.
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百度翻译:Project Lombok是一个java库，它自动插入到编辑器和构建工具中，增强java的性能。
不要再编写另一个getter或equals方法，使用一个注释，您的类有一个功能齐全的生成器，自动记录变量，等等。

    <dependencies>
        <!--Lombok依赖-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
    </dependencies>

@Getter
@Setter
public class Person {
    private String name;
    private Integer age;
}

/**
* @Getter @Setter private int age = 10; //其他写法
* @Setter(AccessLevel.PROTECTED) private String name;
*/

@Getter
@Setter
@ToString
public class Person {
    private String name;
    private Integer age;
}

@Data
public class Person {
    private String name;
    private Integer age;
}

if (param == null) {
        throw new NullPointerException("param is marked @NonNull but is null");
}

@Data
public class Person {
    private String name;
    private Integer age;

    public Person(@NonNull String person) {
        this.name = person;
    }
}

public static void main(String[] args) throws Exception {
    @Cleanup InputStream in = new FileInputStream(args[0]);
    @Cleanup OutputStream out = new FileOutputStream(args[1]);
    byte[] b = new byte[1024];
    while (true) {
        int r = in.read();
        if (r == -1) break;
        out.write(b, 0, r);
    }
}

import lombok.EqualsAndHashCode;

@EqualsAndHashCode
public class EqualsAndHashCodeExample {
  private transient int transientVar = 10;
  private String name;
  private double score;
  @EqualsAndHashCode.Exclude private Shape shape = new Square(5, 10);
  private String[] tags;
  @EqualsAndHashCode.Exclude private int id;
  
  public String getName() {
    return this.name;
  }
  
  @EqualsAndHashCode(callSuper=true)
  public static class Square extends Shape {
    private final int width, height;
    
    public Square(int width, int height) {
      this.width = width;
      this.height = height;
    }
  }
}

import lombok.AccessLevel;
import lombok.RequiredArgsConstructor;
import lombok.AllArgsConstructor;
import lombok.NonNull;

@RequiredArgsConstructor(staticName = "of")
@AllArgsConstructor(access = AccessLevel.PROTECTED)
public class ConstructorExample<T> {
  private int x, y;
  @NonNull private T description;
  
  @NoArgsConstructor
  public static class NoArgsExample {
    @NonNull private String field;
  }
}

import lombok.AccessLevel;
import lombok.experimental.NonFinal;
import lombok.experimental.Value;
import lombok.experimental.Wither;
import lombok.ToString;

@Value public class ValueExample {
  String name;
  @Wither(AccessLevel.PACKAGE) @NonFinal int age;
  double score;
  protected String[] tags;
  
  @ToString(includeFieldNames=true)
  @Value(staticConstructor="of")
  public static class Exercise<T> {
    String name;
    T value;
  }
}

import lombok.Builder;
import lombok.Singular;
import java.util.Set;

@Builder
public class BuilderExample {
  @Builder.Default private long created = System.currentTimeMillis();
  private String name;
  private int age;
  @Singular private Set<String> occupations;
}

import lombok.SneakyThrows;

public class SneakyThrowsExample implements Runnable {
  @SneakyThrows(UnsupportedEncodingException.class)
  public String utf8ToString(byte[] bytes) {
    return new String(bytes, "UTF-8");
  }
  
  @SneakyThrows
  public void run() {
    throw new Throwable();
  }
}

import lombok.Synchronized;

public class SynchronizedExample {
  private final Object readLock = new Object();
  
  @Synchronized
  public static void hello() {
    System.out.println("world");
  }
  
  @Synchronized
  public int answerToLife() {
    return 42;
  }
  
  @Synchronized("readLock")
  public void foo() {
    System.out.println("bar");
  }
}

import lombok.AccessLevel;
import lombok.NonNull;
import lombok.With;

public class WithExample {
  @With(AccessLevel.PROTECTED) @NonNull private final String name;
  @With private final int age;
  
  public WithExample(String name, int age) {
    if (name == null) throw new NullPointerException();
    this.name = name;
    this.age = age;
  }
}

import lombok.Getter;

public class GetterLazyExample {
  @Getter(lazy=true) private final double[] cached = expensive();
  
  private double[] expensive() {
    double[] result = new double[1000000];
    for (int i = 0; i < result.length; i++) {
      result[i] = Math.asin(i);
    }
    return result;
  }
}

import lombok.experimental.Accessors;
import lombok.Getter;
import lombok.Setter;

@Accessors(fluent = true)
public class AccessorsExample {
  @Getter @Setter
  private int age = 10;
}

class PrefixExample {
  @Accessors(prefix = "f") @Getter
  private String fName = "Hello, World!";
}