Java-Class Library-Guava-Table-javaTutorial-php.cn

Java-Class Library-Guava-Table

黄舟

Release： 2017-01-19 13:16:34

Original

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Table

When we need a data structure with multiple indexes, usually we can only use this ugly Map

[code]Test
    public void TableTest(){
        Table<String, Integer, String> aTable = HashBasedTable.create();  

        for (char a = &#39;A&#39;; a <= &#39;C&#39;; ++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)); 
    }

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[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

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Table view:

RowMap() returns a 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;
    }
}

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RangeSet

RangeSet is used to process a series of discontinuous, non-empty ranges. When adding a range to a RangeSet, any consecutive ranges will be automatically merged, and empty ranges will be automatically removed. For example:

[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);
    }

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Note that in cases like merging Range.closed(1, 10) and Range.closedOpen(11, 15), we must first pass in DiscreteDomain.integers by calling Range.canonical(DiscreteDomain) () Process it.

Views of RangeSet

The implementation of RangeSet supports a very rich view, including:

complement(): It is an auxiliary RangeSet, which itself is a RangeSet, because it Contains non-continuous, non-empty ranges.

subRangeSet(Range): Returns an intersection view.

asRanges(): Returns the view of the 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]

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RangeMap that can be iterated

RangeMap provides two views:

asMapOfRanges(): Returns Map

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