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Java-类库-Guava-Table

程序员文章站 2022-05-21 08:56:29
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Table

  当我们需要多个索引的数据结构的时候,通常情况下,我们只能用这种丑陋的Map
[code]Test
    public void TableTest(){
        Table<String, Integer, String> aTable = HashBasedTable.create();  

        for (char a = 'A'; a <= 'C'; ++a) {  
            for (Integer b = 1; b <= 3; ++b) {   
                aTable.put(Character.toString(a), b, String.format("%c%d", a, b));  
            }  
        }  

        System.out.println(aTable.column(2));  
        System.out.println(aTable.row("B"));   
        System.out.println(aTable.get("B", 2));  

        System.out.println(aTable.contains("D", 1));   
        System.out.println(aTable.containsColumn(3));   
        System.out.println(aTable.containsRow("C"));  
        System.out.println(aTable.columnMap()); 
        System.out.println(aTable.rowMap());   

        System.out.println(aTable.remove("B", 3)); 
    }
[code]{A=A2, B=B2, C=C2}
{1=B1, 2=B2, 3=B3}
B2
false
true
true
{1={A=A1, B=B1, C=C1}, 2={A=A2, B=B2, C=C2}, 3={A=A3, B=B3, C=C3}}
{A={1=A1, 2=A2, 3=A3}, B={1=B1, 2=B2, 3=B3}, C={1=C1, 2=C2, 3=C3}}
B3

 Table视图:

  rowMap()返回一个Map

[code]import com.google.common.collect.ClassToInstanceMap;
import com.google.common.collect.HashBasedTable;
import com.google.common.collect.MutableClassToInstanceMap;

public class OtherTest {

    @Test
    public  void ClassToInstanceMapTest() {
        ClassToInstanceMap<String> classToInstanceMapString =MutableClassToInstanceMap.create();
        ClassToInstanceMap<Person> classToInstanceMap =MutableClassToInstanceMap.create();
        Person person= new Person("peida",20);
        System.out.println("person name :"+person.name+" age:"+person.age);
        classToInstanceMapString.put(String.class, "peida");
        System.out.println("string:"+classToInstanceMapString.getInstance(String.class));

        classToInstanceMap.putInstance(Person.class,person);
        Person person1=classToInstanceMap.getInstance(Person.class);
        System.out.println("person1 name :"+person1.name+" age:"+person1.age);
    }
}

class Person {
    public String name;
    public int age;

    Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

 RangeSet

  RangeSet用来处理一系列不连续,非空的range。当添加一个range到一个RangeSet之后,任何有连续的range将被自动合并,而空的range将被自动去除。例如:

[code]   @Test
    public void RangeSetTest(){
        RangeSet<Integer> rangeSet = TreeRangeSet.create();
        rangeSet.add(Range.closed(1, 10));
        System.out.println("rangeSet:"+rangeSet);
        rangeSet.add(Range.closedOpen(11, 15)); 
        System.out.println("rangeSet:"+rangeSet);
        rangeSet.add(Range.open(15, 20));
        System.out.println("rangeSet:"+rangeSet);
        rangeSet.add(Range.openClosed(0, 0)); 
        System.out.println("rangeSet:"+rangeSet);
        rangeSet.remove(Range.open(5, 10)); 
        System.out.println("rangeSet:"+rangeSet);
    }

 注意,像合并Range.closed(1, 10)和Range.closedOpen(11, 15)这样的情况,我们必须先用调用Range.canonical(DiscreteDomain)传入DiscreteDomain.integers()处理一下。

  RangeSet的视图

  RangeSet的实现支持了十分丰富的视图,包括:

  complement():是个辅助的RangeSet,它本身就是一个RangeSet,因为它包含了非连续,非空的range。

  subRangeSet(Range): 返回的是一个交集的视图。

  asRanges():返回可以被迭代的Set

[code]  @Test
    public void RangeMapTest(){
        RangeMap<Integer, String> rangeMap = TreeRangeMap.create();
         rangeMap.put(Range.closed(1, 10), "foo"); 
         System.out.println("rangeMap:"+rangeMap);
         rangeMap.put(Range.open(3, 6), "bar"); 
         System.out.println("rangeMap:"+rangeMap);
         rangeMap.put(Range.open(10, 20), "foo"); 
         System.out.println("rangeMap:"+rangeMap);
         rangeMap.remove(Range.closed(5, 11)); 
         System.out.println("rangeMap:"+rangeMap);
    }

    输出:
    rangeMap:[[1‥10]=foo]
    rangeMap:[[1‥3]=foo, (3‥6)=bar, [6‥10]=foo]
    rangeMap:[[1‥3]=foo, (3‥6)=bar, [6‥10]=foo, (10‥20)=foo]
    rangeMap:[[1‥3]=foo, (3‥5)=bar, (11‥20)=foo]

 RangeMap的视图

  RangeMap提供了两种视图:

  asMapOfRanges():返回Map

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相关标签: Java,Guava,Table