SpringData JPA框架使用时出现JSON循环依赖解决方案

困扰许久的问题终于解决了，之前项目太赶，没有深入学习解决，不甘心，今天再次搭起架子试试，哈哈，终于解决！

　　@ManyToOne(cascade={CascadeType.MERGE,CascadeType.REFRESH},optional=false)
    @JoinColumn(name="approvalForCarId",nullable = false)
    private ApprovalForCar approvalForCar;




　　 @JsonIgnoreProperties(ignoreUnknown = true, value = {"approvalForCar"})
    @OneToMany(mappedBy = "approvalForCar",cascade = { CascadeType.MERGE,CascadeType.REMOVE},fetch = FetchType.EAGER)
    private List<DistributeCar> distributeCars = new ArrayList<>(0);

　　双向关联时json序列化时会出现死循环的情况

jackson解决问题的方式是循环的那一部分不解析
JsonIgnoreProperties配置不解析的属性

g:第一个“栗子"，只有两个类关联，但互相引用了，多对多和一对一这里都适用
Book类上面放入

@JsonIgnoreProperties(ignoreUnknown = true, value =
{"hibernateLazyInitializer", "handler", "fieldHandler"})
public class Book{
... ...

Book类中属性上注解，此属性Author中引用了private Set books;

public class Book{
... ...
@JsonIgnoreProperties(ignoreUnknown = true, value = {"books"})
private Set<Author> authors;
... ...

Author类上面放入

@JsonIgnoreProperties(ignoreUnknown = true, value =
{"hibernateLazyInitializer", "handler", "fieldHandler"})
public class Author{
... ...

Author类中属性上注解，此属性Book中引用了private Set authors;

public class Author{
... ...
@JsonIgnoreProperties(ignoreUnknown = true, value = {"authors"})
private Set<Book> books;
... ...

上面的例子“栗子"过去久远，只对关键需要配置的地方进行了标注
eg:第二个“栗子"，有三个类关联，通过一个中间类关联直接贴代码

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

import javax.persistence.*;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

@Entity
@JsonIgnoreProperties(ignoreUnknown = true, value =
{"hibernateLazyInitializer", "handler", "fieldHandler"})
public class Book implements Serializable {

private static final long serialVersionUID = 1L;

@Id
@TableGenerator(name = "book_generator", table = "tables_sequence", allocationSize = 1, initialValue = 0)
@GeneratedValue(strategy = GenerationType.TABLE, generator = "book_generator")
private int id;
private String name;

@OneToMany(mappedBy = "book", cascade = CascadeType.ALL, orphanRemoval = true)
@JsonIgnoreProperties(ignoreUnknown = true, value = {"book"})
private Set<BookPublisher> bookPublishers;

public Book() {
}

public Book(String name) {
this.name = name;
bookPublishers = new HashSet<>();
}

public int getId() {
return id;
}

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

public String getName() {
return name;
}

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

public Set<BookPublisher> getBookPublishers() {
return bookPublishers;
}

public void setBookPublishers(Set<BookPublisher> bookPublishers) {
this.bookPublishers = bookPublishers;
}
}

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

import javax.persistence.*;
import java.io.Serializable;
import java.util.Set;

@Entity
@JsonIgnoreProperties(ignoreUnknown = true, value =
{"hibernateLazyInitializer", "handler", "fieldHandler"})
public class Publisher implements Serializable {

private static final long serialVersionUID = 1L;

@Id
@TableGenerator(name = "pub_generator", table = "tables_sequence", allocationSize = 1, initialValue = 0)
@GeneratedValue(strategy = GenerationType.TABLE, generator = "pub_generator")
private int id;
private String name;
@OneToMany(mappedBy = "publisher")
@JsonIgnoreProperties(ignoreUnknown = true, value = {"publisher"})
private Set<BookPublisher> bookPublishers;

public Publisher() {

}

public Publisher(String name) {
this.name = name;
}

public int getId() {
return id;
}

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

public String getName() {
return name;
}

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

public Set<BookPublisher> getBookPublishers() {
return bookPublishers;
}

public void setBookPublishers(Set<BookPublisher> bookPublishers) {
this.bookPublishers = bookPublishers;
}
}

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

import javax.persistence.*;
import java.io.Serializable;
import java.util.Date;

@Entity
@Table(name = "book_publisher")
@JsonIgnoreProperties(ignoreUnknown = true, value =
{"hibernateLazyInitializer", "handler", "fieldHandler"})
public class BookPublisher implements Serializable {

@Id
@ManyToOne
@JoinColumn(name = "book_id")
@JsonIgnoreProperties(ignoreUnknown = true, value = {"bookPublishers"})
private Book book;

@Id
@ManyToOne
@JoinColumn(name = "publisher_id")
@JsonIgnoreProperties(ignoreUnknown = true, value = {"bookPublishers"})
private Publisher publisher;

@Column(name = "published_date")
private Date publishedDate;

public Book getBook() {
return book;
}

public void setBook(Book book) {
this.book = book;
}

public Publisher getPublisher() {
return publisher;
}

public void setPublisher(Publisher publisher) {
this.publisher = publisher;
}

public Date getPublishedDate() {
return publishedDate;
}

public void setPublishedDate(Date publishedDate) {
this.publishedDate = publishedDate;
}
}

总结：
本实体中引入了另外一个实体，但另外一个实体也引用了自己无论是集合还是单个实体。jakson在格式化数据的时候会动态过滤掉此属性中对本身对象的引用。