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通过引用放置哈希图并通过复制放置哈希图。我该怎么做后者？另一个问题是数量String[] types并不是真正预先知道的，因此创建多个实例Multiset<String> textAndCount = TreeMultiset.create();并不是很有帮助。我有以下代码，但两种类型的输出是相同的。

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import com.google.common.collect.Multiset;
import com.google.common.collect.TreeMultiset;


public class TestIterator {

private static String[] foobarness  = {"foo", "bar", "ness", "foo", "bar", "foo", "ness", "bar", "foo", "ness", "foo", "bar", "foo", "ness", "bar", "ness", "foo", "bar", "foo", "ness"};

private static String[] foobarness2  = {"bar", "ness", "foo", "bar", "foo", "ness", "bar", "foo", "ness", "foo", "foo", "bar", "foo", "ness", "bar", "foo", "ness", "bar", "foo", "ness", "ness", "bar", "foo", "ness"};

private static String[] types = {"type::1", "type::2"};


public static void main(String[] args) {
    Map<String, Multiset<String>> typeTextCount = 
        new HashMap<String, Multiset<String>>();

    Multiset<String> textAndCount = TreeMultiset.create();
    for (int i = 0; i < types.length; i++) {
        if ("type::1".equals(types[i])) {
            for (String text : foobarness)
                textAndCount.add(text, 1);
        }
        if ("type::2".equals(types[i])) {
            for (String text : foobarness2) 
                textAndCount.add(text, 1);
        }
        typeTextCount.put(types[i], textAndCount);
    }

    Iterator<Entry<String, Multiset<String>>> itTTC = 
        typeTextCount.entrySet().iterator();

    while (itTTC.hasNext()) {
        Map.Entry textCt = (Map.Entry) itTTC.next();
        System.out.println(textCt.getKey() + " :\t" + textCt.getValue());
        itTTC.remove();
    }
}

我的输出来自上面的代码：

type::2 :   [bar x 13, foo x 17, ness x 14]
type::1 :   [bar x 13, foo x 17, ness x 14]

正确的输出应该是：

type::1 :   [bar x 6, foo x 8, ness x 6]
type::2 :   [bar x 7, foo x 9, ness x 8]
4

2 回答 2

4

Multiset<String> textAndCount = TreeMultiset.create()在你的 for 循环内移动。两种“类型”共享同一个多重集，因此您的计数加倍。

你的 for 循环可能看起来像这样：

    for (int i = 0; i < types.length; i++) {
        Multiset<String> textAndCount = TreeMultiset.create();
        if ("type::1".equals(types[i])) {
            for (String text : foobarness)
                textAndCount.add(text, 1);
        }
        if ("type::2".equals(types[i])) {
            for (String text : foobarness2)
                textAndCount.add(text, 1);
        }
        typeTextCount.put(types[i], textAndCount);
    }

当您使用它时，您还可以通过使用 for-each 样式循环来改进地图的迭代。如果您热衷于在迭代时删除每个条目，则可以将 entrySet 包装在 aconsumingIterable中以获得相同的功能。

    for (Entry<String, Multiset<String>> textCt : Iterables.consumingIterable(typeTextCount
            .entrySet())) {
        System.out.println(textCt.getKey() + " :\t" + textCt.getValue());
    }

这会产生输出：

type::2 :   [bar x 7, foo x 9, ness x 8]
type::1 :   [bar x 6, foo x 8, ness x 6]

如果您不喜欢该顺序，我建议您使用 anOrdering来获取您的条目的排序列表。

于 2011-12-15T18:49:06.130 回答
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Multiset<String> textAndCount = TreeMultiset.create();应该在循环内。如果您放置该集合的副本，则输出将是

类型::1 : [bar x 6, foo x 8, ness x 6]
type::2 : [bar x 13, foo x 17, ness x 14]
于 2011-12-15T18:49:39.507 回答