136-137_容器_guava之_实用功能_Multiset_Multimap_BiMap_Table

Multiset

• Test05_MultiSet.java

package guava.collection;

import java.util.Set;

import com.google.common.collect.HashMultiset;
import com.google.common.collect.Multiset;
/**
 * 统计单词出现的次数
 * 1.HashMap 分拣存储+面向对象思维 -->判断
 * 2.Multiset: 无序+可重复/增强了可读性 +操作简单
 * 创建：Multiset HashMultiset.create();
 * 获取：Set Multiset.elementSet();
 * 计数： temp+"-->"+Multiset.count(temp)
 */
public class Test05_MultiSet {
public static void main(String[] args) {
        String str ="this is a cat and that is a mice where is the food";
//分割字符串
        String[] strArray =str.split(" ");
//存储到Multiset中
        Multiset<String> set =HashMultiset.create();
for(String strTemp:strArray){
            set.add(strTemp);
        }

//获取所有的单词 Set
        Set<String> letters =set.elementSet();
for(String temp:letters){
            System.out.println(temp+"-->"+set.count(temp));
        }
    }
}

Multimap

• Test06_MultiMap.java

package guava.collection;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;
/**
 * 分析查看 教师 教授的每门课程
 * Multimap :key-value key可以重复
 */
public class Test06_MultiMap {
    public static void main(String[] args) {
        test();
//      test2();
    }

    public static void test(){
        Multimap<String,String> teachers =ArrayListMultimap.create();
        teachers.put("邓爷爷", "改革开放");
        teachers.put("*", "三个代表");
        teachers.put("*", "科学发展观");
        teachers.put("*", "八荣八耻");
        teachers.put("*", "和谐社会");
        teachers.put("习主席", "....");
Set<String> keyset=teachers.keySet();
        for(String key:keyset){
            List<String> list=(List<String>) teachers.get(key);
            System.out.println(key+"-->"+list);
        }
    }
    public static void test2(){
        Map<String,String> cours =new HashMap<String,String>();
        //加入测试数据
        cours.put("改革开放", "邓爷爷");
        cours.put("三个代表", "*");
        cours.put("科学发展观", "*");
        cours.put("和谐社会", "*");
        cours.put("八荣八耻", "*");
        cours.put("....", "习主席");

        //Multimap
        Multimap<String,String> teachers =ArrayListMultimap.create();

        //迭代器
        Iterator<Map.Entry<String,String>> it =cours.entrySet().iterator();
        while(it.hasNext()){
            Map.Entry<String,String> entry =it.next();
            String key =entry.getKey(); //课程
            String value =entry.getValue(); //教师

            //教师 -->课程
            teachers.put(value, key);
        }

        //查看Multimap
Set<String> keyset =teachers.keySet();
        for(String key:keyset){
            Collection<String> col =teachers.get(key);
            System.out.println(key+"-->"+col);
        }
    }
}

BiMap

• Test07_BiMap.java

package guava.collection;

import com.google.common.collect.BiMap;
import com.google.common.collect.HashBiMap;
/**
 * HashMap 键唯一,值可以重复
 * BiMap:双向Map(Bidirectional Map) 键与值都不能重复(unique -valued map)
 */
public class Test07_BiMap {
public static void main(String[] args) {
        BiMap<String,String> bimap=HashBiMap.create();
        bimap.put("bjsxt", "[e-mail]");
        bimap.put("good","[e-mail]");
//通过邮箱找用户
        String user =bimap.inverse().get("[e-mail]");
        System.out.println(user);
        System.out.println(bimap.inverse().inverse()==bimap);
    }
}

Table

• Test08_Table.java

package guava.collection;

import java.util.Map;
import java.util.Set;

import com.google.common.collect.HashBasedTable;
import com.google.common.collect.Table;
import com.google.common.collect.Table.Cell;
import com.google.common.collect.Tables;
/**
 * 双键的Map -->Table -->rowKey+columnKey+value
 * Table<R, C, V> ->HashBasedTable<R, C, V>.create()
 * 方法
 * 1.所有的行数据:.cellSet()->Set<Cell<R, C, V>>
 * 单行：<Cell<R, C, V>> 获取.getRowKey() .getColumnKey() .getValue()
 * 2.获取rowkey列:.rowKeySet()
 * 3.获取columnkey列:.columnKeySet()
 * row(rowKey)->Map<rowkey,value>
 * column(columnKey)->Map<columnkey,value>
 * 4.获取value列: values()
 * 5.转换(将rowKey和columnKey对调位置)
 * Tables.transpose(tables);
 */
public class Test08_Table {
    public static void main(String[] args) {
        Table<String,String,Integer> tables=HashBasedTable.create();
        //测试数据
        tables.put("a", "javase", 80);
        tables.put("b", "javase", 90);
        tables.put("a", "oracle", 100);
        tables.put("c", "oracle", 95);

        //所有的行数据
Set<Cell<String,String,Integer>> cells =tables.cellSet();
        for(Cell<String,String,Integer> temp:cells){
            System.out.println(temp.getRowKey()+"-->"+temp.getColumnKey()+"-->"+temp.getValue());
        }

        System.out.println("==========学生查看成绩==============");
        System.out.print("学生\t");
        //所有的课程
Set<String> cours =tables.columnKeySet();
        for(String t:cours){
            System.out.print(t+"\t");
        }
        System.out.println();
        //所有的学生
Set<String> students =tables.rowKeySet();
        for(String stu:students){
            System.out.print(stu+"\t");
            Map<String,Integer> scores =tables.row(stu);
            for(String c:cours){
                System.out.print(scores.get(c)+"\t");
            }
            System.out.println();
        }

        System.out.println("==========课程查看成绩==============");
        System.out.print("课程\t");
        //所有的学生
Set<String> stuSet =tables.rowKeySet();
        for(String stu:stuSet){
            System.out.print(stu+"\t");
        }
        System.out.println();
        //所有的课程
Set<String> courSet =tables.columnKeySet();
        for(String c:courSet){
            System.out.print(c+"\t");
            Map<String,Integer> scores =tables.column(c);
            for(String s:stuSet){
                System.out.print(scores.get(s)+"\t");
            }
            System.out.println();
        }

        System.out.println("===========转换===========");
        Table<String,String,Integer> tables2 =Tables.transpose(tables);
        //所有的行数据
Set<Cell<String,String,Integer>> cells2 =tables2.cellSet();
        for(Cell<String,String,Integer> temp:cells2){
            System.out.println(temp.getRowKey()+"-->"+temp.getColumnKey()+"-->"+temp.getValue());
        }
    }
}