guava处理字符串与List之间，字符串与map之间的转换<转>

 import static org.junit.Assert.*;

 import java.util.List;
 import java.util.Map;

 import org.junit.Test;

 import com.google.common.base.Joiner;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;

 public class Guava {

     /**
      * list转换为字符串
      */
     @Test
     public void joinTest(){
         List<String> names = Lists.newArrayList("John", "Jane", "Adam", "Tom");
         String result = Joiner.on(",").join(names);

         assertEquals(result, "John,Jane,Adam,Tom");
     }

     /**
      * map转换为字符串
      */
     @Test
     public void whenConvertMapToString_thenConverted() {
         Map<String, Integer> salary = Maps.newHashMap();
         salary.put("John", 1000);
         salary.put("Jane", 1500);
         String result = Joiner.on(" , ").withKeyValueSeparator(" = ")
                                         .join(salary);
         System.out.println(result);
     }

     /**
      * list转String，跳过null
      */
     @Test
     public void whenConvertListToStringAndSkipNull_thenConverted() {
         List<String> names = Lists.newArrayList("John", null, "Jane", "Adam", "Tom");
         String result = Joiner.on(",").skipNulls().join(names);
         System.out.println(result);
         assertEquals(result, "John,Jane,Adam,Tom");
     }

     /**
      * list转String，将null变成其他值
      */
     @Test
     public void whenUseForNull_thenUsed() {
         List<String> names = Lists.newArrayList("John", null, "Jane", "Adam", "Tom");
         String result = Joiner.on(",").useForNull("nameless").join(names);
         System.out.println(result);
         assertEquals(result, "John,nameless,Jane,Adam,Tom");
     }

     /**
      * String to List
      */
     @Test
     public void whenCreateListFromString_thenCreated() {
         String input = "apple - banana - orange";
         List<String> result = Splitter.on("-").trimResults().splitToList(input);
         System.out.println(result);
         //assertThat(result, contains("apple", "banana", "orange"));
     }

     /**
      * String to Map
      */
     @Test
     public void whenCreateMapFromString_thenCreated() {
         String input = "John=first,Adam=second";
         Map<String, String> result = Splitter.on(",")
                                              .withKeyValueSeparator("=")
                                              .split(input);

         assertEquals("first", result.get("John"));
         assertEquals("second", result.get("Adam"));
     }

     /**
      * 多个字符进行分割
      */
     @Test
     public void whenSplitStringOnMultipleSeparator_thenSplit() {
         String input = "apple.banana,,orange,,.";
         List<String> result = Splitter.onPattern("[.|,]")
                                       .omitEmptyStrings()
                                       .splitToList(input);
         System.out.println(result);
     }

     /**
      * 每隔多少字符进行分割
      */
     @Test
     public void whenSplitStringOnSpecificLength_thenSplit() {
         String input = "Hello world";
         List<String> result = Splitter.fixedLength(3).splitToList(input);
         System.out.println(result);
     }

     /**
      * 限制分割多少字后停止
      */
     @Test
     public void whenLimitSplitting_thenLimited() {
         String input = "a,b,c,d,e";
         List<String> result = Splitter.on(",")
                                       .limit(4)
                                       .splitToList(input);

         assertEquals(4, result.size());
         System.out.println(result);
     }

 }

转自http://blog.csdn.net/sunhuwh/article/details/41291515