StackOverflowError异常处理

 在java虚拟机规范中，虚拟机栈和本地方法栈都会出现StackOverflowError和OutofMemoryError，程序计数器是java虚拟机中唯一一块不会产生error的内存区域，StackOverflowError代表的是，当栈深度超过虚拟机分配给线程的栈大小时就会出现此error，OutofMemoryError代表的是，当再申请新的内存时，虚拟机分配给线程的内存大小中无法再分配新的内存，就会出现此error。

现象：对象互相嵌套设置出现StackOverflowError异常

对象A：

package com.test;

import com.wordnik.swagger.annotations.ApiModel;
import com.wordnik.swagger.annotations.ApiModelProperty;

import java.io.Serializable;
import java.util.List;

/**
 * test-manager
 * Created by xian.juanjuan on 2017-5-11 16:25.
 */
@ApiModel(description = "test-manager   Created by xian.juanjuan on 2017-5-11 16:25.")
public class Student implements Serializable{

    private static final long serialVersionUID = -4895104060364320456L;
    /**
     * 用户ID
     */
    @ApiModelProperty(value = "用户ID")
    private String userId;

    /**
     * 用户名
     */
    @ApiModelProperty(value = "用户名")
    private String userName;

    /**
     * 分数
     */
    @ApiModelProperty(value = "分数")
    private List scores;


    /**
     * 获取 用户ID
     */
    public String getUserId() {
        return this.userId;
    }

    /**
     * 设置 用户ID
     */
    public void setUserId(String userId) {
        this.userId = userId;
    }

    /**
     * 获取 用户名
     */
    public String getUserName() {
        return this.userName;
    }

    /**
     * 设置 用户名
     */
    public void setUserName(String userName) {
        this.userName = userName;
    }

    /**
     * 获取 分数
     */
    public List getScores() {
        return this.scores;
    }

    /**
     * 设置 分数
     */
    public void setScores(List scores) {
        this.scores = scores;
    }
}

对象B：

package com.test;

import com.wordnik.swagger.annotations.ApiModel;
import com.wordnik.swagger.annotations.ApiModelProperty;

import java.io.Serializable;

/**
 * test-manager
 * Created by xian.juanjuan on 2017-5-11 16:25.
 */
@ApiModel(description = "test-manager   Created by xian.juanjuan on 2017-5-11 16:25.")
public class Score implements Serializable {

    private static final long serialVersionUID = -6345327076401038020L;
    /**
     * 分数
     */
    @ApiModelProperty(value = "分数")
    private String subject;

    /**
     * 科目
     */
    @ApiModelProperty(value = "科目")
    private double score;

    /**
     * 学生信息
     */
    @ApiModelProperty(value = "学生信息")
    private Student student;

    /**
     * 获取 分数
     */
    public String getSubject() {
        return this.subject;
    }

    /**
     * 设置 分数
     */
    public void setSubject(String subject) {
        this.subject = subject;
    }

    /**
     * 获取 科目
     */
    public double getScore() {
        return this.score;
    }

    /**
     * 设置 科目
     */
    public void setScore(double score) {
        this.score = score;
    }

    /**
     * 获取 学生信息
     */
    public Student getStudent() {
        return this.student;
    }

    /**
     * 设置 学生信息
     */
    public void setStudent(Student student) {
        this.student = student;
    }
}

测试

package com.test;

import com.alibaba.fastjson.JSONObject;

import java.util.ArrayList;
import java.util.List;

/**
 * test-manager
 * Created by xian.juanjuan on 2017-5-11 16:25.
 */
public class Test {

    public static void main(String[] args){

        Student student = new Student();
        student.setUserId("001");
        student.setUserName("小神经");

        Score score = new Score();
        score.setSubject("语文");
        score.setScore(100);
        score.setStudent(student);
        // TODO score入库

        List scores = new ArrayList<>();
        scores.add(score);

        student.setScores(scores);
        //TODO student入库

        System.out.print("运行完毕，学生信息为："+ JSONObject.toJSONString(student));
    }
}

运行结果：

"C:\Program Files\Java\jdk1.8.0_71\bin\java" -Didea.launcher.port=7532 "-Didea.launcher.bin.path=D:\soft\IntelliJ IDEA 2016.1.1\bin" -classpath C:\Users\xian.juanjuan\AppData\Local\Temp\classpath92.jar -Dfile.encoding=UTF-8 com.intellij.rt.execution.application.AppMain com.jyall.goods.product.service.Test
运行完毕，学生信息为：{"scores":[{"score":100,"student":{"$ref":"$"},"subject":"语文"}],"userId":"001","userName":"小神经"}
Process finished with exit code 0

debug看运行过程中的参数信息：

score和student之间出现循环赋值，如果这里的对象属性比较多的时候，这种循环调用之后会导致该线程的堆栈异常，最终导致StackOverflowError异常；如何避免这种情况发生呢？可以克隆或者新建对象：

例如：

package com.jyall.goods.product.service;

import com.alibaba.fastjson.JSONObject;
import org.springframework.beans.BeanUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * goods-main-manager
 * Created by xian.juanjuan on 2017-5-11 16:25.
 */
public class Test {

    public static void main(String[] args){

        Student student = new Student();
        student.setUserId("001");
        student.setUserName("小神经");

        Score score = new Score();
        score.setSubject("语文");
        score.setScore(100);
        //避免循环调用出现StackOverflowError异常，这里用临时对象studentTemp
        Student studentTemp = new Student();
        BeanUtils.copyProperties(student,studentTemp);
        score.setStudent(studentTemp);
        // TODO score入库

        List scores = new ArrayList<>();
        scores.add(score);

        student.setScores(scores);
        //TODO student入库

        System.out.print("运行完毕，学生信息为："+ JSONObject.toJSONString(student));
    }
}

互相嵌套过程中不会出现死循环现象~