业务DTO定义实践_JAVA_编程开发_程序员俱乐部

一.定义抽象类，重写toString()方法

???? 在toString()方法中调commons-lang.jar的ToStringBuilder类的reflectionToString方法。这样，在日志输出时直接输出业务DTO对象，就能输出对象的属性及属性值。

class="java">package com.bijian.study;

import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;

public abstract class AbstractDTO implements java.io.Serializable {

    private static final long serialVersionUID = 639200629041717L;

    public String toString() {
        return ToStringBuilder.reflectionToString(this, ToStringStyle.MULTI_LINE_STYLE);
    }
}

?

二.定义业务DTO对象，重写hashCode()、equals()方法，并实现Comparable接口

package com.bijian.study;

public class PersonDTO extends AbstractDTO implements Comparable {

    //编码
    private String code;
    
    //姓名
    private String name;
    

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public String getName() {
        return name;
    }

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

    /* (non-Javadoc)
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((code == null) ? 0 : code.hashCode());
        return result;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof PersonDTO)) {
            return false;
        }
        PersonDTO other = (PersonDTO) obj;
        if (code == null) {
            if (other.code != null) {
                return false;
            }
        } else if (!code.equals(other.code)) {
            return false;
        }
        return true;
    }

    public int compareTo(Object object) {
        String thisCode = this.getCode();
        String anotherCode = ((PersonDTO) object).getCode();
        return thisCode.compareTo(anotherCode);
    }
    
    public static void main(String[] args) {
        PersonDTO personDTO = new PersonDTO();
        personDTO.setCode("123");
        personDTO.setName("Test");
        System.out.println(personDTO);
    }
}

?运行PersonDTO类的main方法，打印结果如下所示：

com.bijian.study.PersonDTO@173a10f[
  code=123
  name=Test
]