在Java编程中，经常要对List集合进行排序，因此对List排序的各种情况进行总结，希望对各位读者有所帮助。
1.单属性变量List排序1.1按照变量属性升序，降序排序
- private void singleVariableSort1(){
- List
list = Arrays.asList(10,1,6,4,8,7,9,3,2,5); - System.out.println("原始数据：");
- list.forEach(n ->{System.out.print(n+", ");});
- System.out.println("");
- System.out.println("升序排列：");
- Collections.sort(list); // 升序排列
- list.forEach(n ->{System.out.print(n+", ");});
- System.out.println("");
- System.out.println("降序排列：");
- Collections.reverse(list); // 倒序排列
- list.forEach(n ->{System.out.print(n+", ");});
- }
1.2按照自定义的顺序排序
2.对象List排序
- private void singleVariableSort2(){
- List
list = Arrays.asList("北京","上海","北京","广州","广州","上海","北京","上海"); - List
sortRule = Arrays.asList("北京","上海","广州"); - System.out.println("原始数据：");
- list.forEach(n ->{System.out.print(n+", ");});
- System.out.println("");
- System.out.println("排序规则：");
- sortRule.forEach(n ->{System.out.print(n+", ");});
- System.out.println("");
- System.out.println("正序排列：");
- Collections.sort(list, new Comparator
() - {
- public int compare(String a1, String a2)
- {
- int io1 = sortRule.indexOf(a1);
- int io2 = sortRule.indexOf(a2);
- return io1 - io2;
- }
- });
- list.forEach(n ->{System.out.print(n+", ");});
- System.out.println("");
- System.out.println("倒序排列：");
- Collections.sort(list, new Comparator
() - {
- public int compare(String a1, String a2)
- {
- int io1 = sortRule.indexOf(a1);
- int io2 = sortRule.indexOf(a2);
- return io2 - io1;
- }
- });
- list.forEach(n ->{System.out.print(n+", ");});
- }
2.1按照对象单属性升序，降序排序
- private void entitySort1(){
- //Student 的 list 集合
- List
students = new ArrayList <>(); - students.add(new Student("张三",90,180,"电气学院","北京"));
- students.add(new Student("李四",80,165,"计算机学院","上海"));
- students.add(new Student("王五",91,170,"财经学院","上海"));
- students.add(new Student("赵明",80,182,"计算机学院","北京"));
- students.add(new Student("钱海",75,181,"计算机学院","广州"));
- students.add(new Student("孙理",82,172,"财经学院","上海"));
- students.add(new Student("周伟",90,168,"电气学院","广州"));
- students.add(new Student("郑亮",80,178,"财经学院","广州"));
- System.out.println("原始数据：");
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+ s.getCollege()+""+s.getAddress());});
- System.out.println("按照分数升序排序：");
- students.sort(comparing(Student::getScore));
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+ s.getCollege()+""+s.getAddress());});
- System.out.println("按照分数降序排序：");
- students.sort(comparing(Student::getScore).reversed());
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- }
2.2按照对象多属性升序，降序排序
- private void entitySort2(){
- //Student 的 list 集合
- List
students = new ArrayList <>(); - students.add(new Student("张三",90,180,"电气学院","北京"));
- students.add(new Student("李四",80,165,"计算机学院","上海"));
- students.add(new Student("王五",91,170,"财经学院","上海"));
- students.add(new Student("赵明",80,182,"计算机学院","北京"));
- students.add(new Student("钱海",75,181,"计算机学院","广州"));
- students.add(new Student("孙理",82,172,"财经学院","上海"));
- students.add(new Student("周伟",90,168,"电气学院","广州"));
- students.add(new Student("郑亮",80,178,"财经学院","广州"));
- System.out.println("原始数据：");
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- System.out.println("按照分数降序排序,当分数相同时, 按照身高升序排序");
- students.sort(comparing(Student::getScore).reversed().thenComparing(Student::getHeight));
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- System.out.println("按照分数降序排序,当分数相同时, 按照身高降序排序");
- Collections.sort(students, new Comparator
() - {
- public int compare(Student student1, Student student2)
- {
- if(student1.getScore().equals(student2.getScore())){
- return student2.getHeight() - student1.getHeight();
- }else{
- return student2.getScore() - student1.getScore();
- }
- }
- });
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- }
2.3按照对象自定义单属性的顺序排序
- private void entitySort3(){
- //Student 的 list 集合
- List
students = new ArrayList <>(); - students.add(new Student("张三",90,180,"电气学院","北京"));
- students.add(new Student("李四",80,165,"计算机学院","上海"));
- students.add(new Student("王五",91,170,"财经学院","上海"));
- students.add(new Student("赵明",80,182,"计算机学院","北京"));
- students.add(new Student("钱海",75,181,"计算机学院","广州"));
- students.add(new Student("孙理",82,172,"财经学院","上海"));
- students.add(new Student("周伟",90,168,"电气学院","广州"));
- students.add(new Student("郑亮",80,178,"财经学院","广州"));
- System.out.println("原始数据：");
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- System.out.println("自定义按照地区（北京,上海,广州）排序：");
- List
addressOrder = Arrays.asList("北京","上海","广州"); - Collections.sort(students, new Comparator
() - {
- public int compare(Student student1, Student student2)
- {
- int io1 = addressOrder.indexOf(student1.getAddress());
- int io2 = addressOrder.indexOf(student2.getAddress());
- return io1 - io2;
- }
- });
- students.forEach( s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- }
2.4按照对象自定义多属性的顺序排序
- private void entitySort4(){
- //Student 的 list 集合
- List
students = new ArrayList <>(); - students.add(new Student("张三",90,180,"电气学院","北京"));
- students.add(new Student("李四",80,165,"计算机学院","上海"));
- students.add(new Student("王五",91,170,"财经学院","上海"));
- students.add(new Student("赵明",80,182,"计算机学院","北京"));
- students.add(new Student("钱海",75,181,"计算机学院","广州"));
- students.add(new Student("孙理",82,172,"财经学院","上海"));
- students.add(new Student("周伟",90,168,"电气学院","广州"));
- students.add(new Student("郑亮",80,178,"财经学院","广州"));
- System.out.println("原始数据：");
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- System.out.println("先按照学院（电气学院,计算机学院,财经学院）排序， 当学院相同时,按照地区（北京,上海,广州）排序");
- List
collegeOrder = Arrays.asList("电气学院","计算机学院","财经学院"); - List
addressOrder = Arrays.asList("北京","上海","广州"); - Collections.sort(students, new Comparator
() - {
- public int compare(Student student1, Student student2)
- {
- if(student1.getCollege().equals(student2.getCollege())){
- int io1 = addressOrder.indexOf(student1.getAddress());
- int io2 = addressOrder.indexOf(student2.getAddress());
- return io1 - io2;
- }else{
- int io1 = collegeOrder.indexOf(student1.getCollege());
- int io2 = collegeOrder.indexOf(student2.getCollege());
- return io1 - io2;
- }
- }
- });
- students.forEach( s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- }
2.5按照对象属性自定义混合排序
- private void entitySort5(){
- //Student 的 list 集合
- List
students = new ArrayList <>(); - students.add(new Student("张三",90,180,"电气学院","北京"));
- students.add(new Student("李四",80,165,"计算机学院","上海"));
- students.add(new Student("王五",91,170,"财经学院","上海"));
- students.add(new Student("赵明",80,182,"计算机学院","北京"));
- students.add(new Student("钱海",75,181,"计算机学院","广州"));
- students.add(new Student("孙理",82,172,"财经学院","上海"));
- students.add(new Student("周伟",90,168,"电气学院","广州"));
- students.add(new Student("郑亮",80,178,"财经学院","广州"));
- System.out.println("原始数据：");
- students.forEach(s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- //先按照分数从高到低排序,当分数相同时,然后按照地区（北京,上海,广州）排序
- List
addressOrder = Arrays.asList("北京","上海","广州"); - Collections.sort(students, new Comparator
() - {
- public int compare(Student student1, Student student2)
- {
- if(student1.getScore().equals(student2.getScore())){
- int io1 = addressOrder.indexOf(student1.getAddress());
- int io2 = addressOrder.indexOf(student2.getAddress());
- return io1 - io2;
- }else{
- return student2.getScore() - student1.getScore();
- }
- }
- });
- System.out.println("");
- System.out.println("先按照分数从高到低排序,当分数相同时,然后按照地区（北京,上海,广州）排序：");
- students.forEach( s ->{
- System.out.println(s.getName()+" "+ s.getScore()+" "+s.getHeight()+" "+s.getCollege()+""+s.getAddress());});
- }
2.6按照对象单属性升序，降序排序(float类型)
- private void entitySort6(){
- //Shop 的 list 集合
- List
shops = new ArrayList<>(); - shops.add( new Shop( "华润万家", 20200921, ( float) 10000.25));
- shops.add( new Shop( "华润万家", 20200922, ( float) 20000.26));
- shops.add( new Shop( "华润万家", 20200923, ( float) 9999.37));
- shops.add( new Shop( "华润万家", 20200924, ( float) 12587.86));
- shops.add( new Shop( "华润万家", 20200925, ( float) 15798.65));
- System.out.println( "原始数据：");
- shops. forEach(s ->{
- System.out.println(s.getName() + " " + s.getDate() + " " + s.getIncome() );
- });
- System.out.println( "按照收入升序排序：");
- shops.sort(comparing(Shop::getIncome));
- shops. forEach(s ->{
- System.out.println(s.getName() + " " + s.getDate() + " " + s.getIncome());
- });
- System.out.println( "按照收入降序排序：");
- shops.sort(comparing(Shop::getIncome).reversed());
- shops. forEach(s ->{
- System.out.println(s.getName() + " " + s.getDate() + " " + s.getIncome());
- });
- }
