Builder模式创建pojo类

builder模式优点在于可以简化对象赋值的过程，也可以在设计类的时候，设置哪些属性必须赋值，哪些不是必须赋值的，代码如下：

public class PathOBJ {

	private String path_input = "";
	private String path_output = "";
	private String run_sign = "";

	public PathOBJ(Build build) {
		this.path_input = build.path_input;
		this.path_output = build.path_output;
		this.run_sign = build.run_sign;
	}

	public static class Build {
		private String path_input = "";
		private String path_output = "";
		private String run_sign = "";

		public Build setPath_input(String path_input) {
			this.path_input = path_input;
			return this;
		}
		
		public Build setPath_output(String path_output) {
			this.path_output = path_output;
			return this;
		}

		public Build setRun_sign(String run_sign) {
			this.run_sign = run_sign;
			return this;
		}

		public PathOBJ create() {
			return new PathOBJ(this);
		}
	}
｝

也可以设置get方法，便于后期获取属性，或者修改pathOBJ类属性的访问修饰符。