public class Lll {public static void main(String[] args) {Bj bj =new Bj();bj.setName("三年一班");Bz bzh =new Bz();bzh.setName("周杰倫");//設置班長 bj.setBz(bzh);//獲取三年一班的班長Bz ban = bj.getBz();System.out.println("三年一班的班長是："+ban.getName());//查找周杰倫所在的班級 bzh.setBj(bj);System.out.println("周杰倫所在的班級是:"+bzh.getBj().getName());}} class Bj{private String name;private Bz bz;public Bj(){}public String getName() {return name;}public void setName(String name) {this.name = name;}//bz屬性的賦值和提取public Bz getBz() {return bz;}public void setBz(Bz bz) {this.bz = bz;}public String getInfo(){return name+"班級名字";}} class Bz{private String name;private Bj bj;public Bz(){}public String getName() {return name;}public void setName(String name) {this.name = name;}//班級屬性的賦值和提取方法public Bj getBj() {return bj;}public void setBj(Bj bj) {this.bj = bj;}public String getInfo(){return name+"班長姓名";}}

?一對多

package lxd;public class Lxd{public static void main(String[] args) {//1初始化數(shù)據(jù)Dept d1 = new Dept("財務部","濟南");Emp e1 = new Emp("張三","總監(jiān)");Emp e2 = new Emp("李四","經(jīng)理");Emp e3 = new Emp("王五","員工");//2設置關系 e1.setDept(d1);e2.setDept(d1);e3.setDept(d1);d1.setEmp(new Emp[]{e1,e2,e3});//3獲取數(shù)據(jù) System.out.println(e3.getDept().getInfo());for (int i = 0; i < d1.getEmp().length; i++) {System.out.println(d1.getEmp()[i].getInfo());}}} class Emp{ //員工類private String ename;private String job;private Dept dept; //部門屬性public Emp(){};public Emp(String ename,String job){this.ename = ename;this.job = job;}public Dept getDept(){return dept;}public void setDept(Dept dept){this.dept = dept;}public String getInfo(){return "雇員姓名："+ename+"，職位"+job;} }class Dept{ //部門類private String dname;private String loc ;private Emp[] emps; //多個員工屬性public Dept(){};public Dept(String dname,String loc){this.dname = dname;this.loc = loc;}public void setEmp(Emp[] emps){this.emps = emps;}public Emp[] getEmp(){return emps;}public String getInfo(){return "部門名稱"+dname+"地址："+loc;} }

多對多

package lxd;public class Lxd{public static void main(String[] args) {//初始值Stu s1 = new Stu("張三");Stu s2 = new Stu("李四");Stu s3 = new Stu("王五");Course c1 = new Course("Java");Course c2 = new Course("Oracle");Course c3 = new Course("Python");//設置關系 s1.setCourses(new Course[]{c1,c3});s2.setCourses(new Course[]{c2});s3.setCourses(new Course[]{c1,c2,c3});c1.setStus(new Stu[]{s1,s3});c2.setStus(new Stu[]{s2,s3});c3.setStus(new Stu[]{s1,s3});//取數(shù)據(jù)//張三選的課System.out.println(s1.getName()+"-"+"所選課程");for (int i = 0; i < s1.getCourses().length; i++) {System.out.println(s1.getCourses()[i].getName());}}} class Stu{private String name;private Course[] courses; //課程屬性數(shù)組public Stu(){}public Stu(String name){this.name = name;}public String getName(){return name ;}public void setName(String name){this.name = name;}public Course[] getCourses(){return courses;}public void setCourses(Course[] courses){this.courses = courses;}} class Course{private String name;private Stu[] stus;//構(gòu)造public Course(){}public Course(String name ){this.name = name;}//方法public String getName(){return name;}public void setName(String name){this.name = name;}public Stu[] getStus(){return stus;}public void setStus(Stu[] stus){this.stus = stus;}// public String getInfo(){return "課程"+name;} }

?

轉(zhuǎn)載于:https://www.cnblogs.com/xiandong/p/7932520.html

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