Rumah >Java >javaTutorial >Java-类库-Guava-Table
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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