Apache Commons Collections MultiValuedMap 按多个字段过滤数据

Question

下面的数据是内存中的集合 java ArrayList，需要从这个集合中根据两个字段（VRNT_CD 和 ITM_NB)

VRNT_CD ITM_NB COMMT_TEXT
 10      A0A     SampleText1
 10      A0A     SampleText2
 10      A0A     SampleText3
 10      A0B     SampleText4
 10      A0C     SampleText5
 20      A0A     SampleText6
 20      A0A     SampleText7
 20      A0B     SampleText8
 20      A0C     SampleText9
 30      A0A     SampleText10
 30      A0A     SampleText11
 30      AOB     SampleText12
 30      A0C     SampleText13
 30      A0C     SampleText14

如上所述，上面 table 中的每一行都映射到下面 java 对象

public class SummaryDataOracle {

    private String funcCode;
    private String commentText;
    private String variantCd;
    private String itemNB;
  //setters //getters
}

上面table的集合表示为List<SummaryDataOracle>，需要根据下面的key

使用集合对象生成map

public class VssKey {

    private String funCode;
    private String varntCode;
    private String itemNb;

    //setters //getters // equals // hashcode

}

因此生成的集合应具有以下数据结构

AOA   10    SampleText1
            SampleText2
            SampleText3

      20    SampleText6
            SampleText7

      30    SampleText10
            SampleText11

AOB   10    SampleText4

      20    SampleText8

      30    SampleText12

AOC   10    SampleText5

      20    SampleText9

      30    SampleText13
            SampleText14

Answer 1

通过实施以下对象并使用 apache commons MultiValuedMap.

解决了问题

public class VssKey {

     // getterrs
     // setters
     // equals
     // hashcode
}

    MultiValuedMap<VssKey, String> partNumberVarientMap = new ArrayListValuedHashMap<>();

            for (SummaryDataOracle summaryDataOracle : summeryDataOracleList) {

                VssKey key = new VssKey(summaryDataOracle);

                String varntText = null;
                if (!StringUtils.isEmpty(summaryDataOracle.getVariantSmText())) {
                    varntText = summaryDataOracle.getVariantSmText().trim();
                }

                partNumberVarientMap.put(key, varntText);    
}

Apache Commons Collections MultiValuedMap 按多个字段过滤数据

Apache Commons Collections MultiValuedMap to filter data by multiple fields

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guava