String字符串处理系列和json转化

通过guava处理字符串

1、pom

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>23.0</version>
</dependency>

2、字符串拼接

// 将list 用‘;’拼接，并跳过 null
final List<String> stringArrayList = Lists.newArrayList("aadf", "ldksf", "", "kjslfu", "ekfkkld");
final String join = Joiner.on(";").skipNulls().join(stringArrayList);
System.out.println("join = " + join);  // join = aadf;ldksf;kjslfu;ekfkkld

final String join1 = Joiner.on(" - ").join("adfs", 'd', 1233, 90, "wew");
System.out.println("join1 = " + join1); // join1 = adfs - d - 1233 - 90 - wew

 

3、字符串拆分

String a = "aadf;ldksf;;kjslfu;ekfkkld";
// 通过';'切割（支持正则），忽略空出字符串，结果字符串前后空格删除
final List<String> strings = Splitter.on(";").omitEmptyStrings().trimResults().splitToList(a); 
System.out.println("strings = " + strings);

4、CharMatcher

String a = "kjluwefjo23749823ljk12340325132lk1r2137";
final String s = CharMatcher.javaDigit().retainFrom(a);
System.out.println("s = " + s);  // 237498231234032513212137

5、CaseFormat (未测)

LOWER_CAMEL    lowerCamel
LOWER_HYPHEN    lower-hyphen
LOWER_UNDERSCORE    lower_underscore
UPPER_CAMEL    UpperCamel
UPPER_UNDERSCORE    UPPER_UNDERSCORE

6、字符串格式化

String lkl = MessageFormat.format("aaa{0}ccc{1}", "bbb","ddd");    // aaabbbcccddd

 

字符串格式化工具

pom

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.4</version>
</dependency>

代码

        Map<String, String> map = new HashMap<>();
        map.put("a", "kkkkkk");
        String str = "kljsfue kdjsfu ${a}";
        final StrSubstitutor strSubstitutor = new StrSubstitutor(map);
        final String replace = strSubstitutor.replace(str);
        System.out.println("replace = " + replace);  // replace = kljsfue kdjsfu kkkkkk

 

通过fastjson处理字符串

1、pom

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.69</version>
</dependency>

2、其它类型转json

// list转json
List<String> stringArrayList = Lists.newArrayList("aadf", "ldksf", "", "kjslfu", "ekfkkld");
String s = JSONObject.toJSONString(stringArrayList);  // ["aadf","ldksf","","kjslfu","ekfkkld"]

// 对象转json
Answer answer = new Answer();
answer.setUserId("kk");
answer.setId(12);
String s1 = JSONObject.toJSONString(answer);  //{"id":12,"userId":"kk"}

3、json转其它类型

// json 转map
String mapJson = "{\"id\":12,\"userId\":\"kk\"}";
final Map<String,String> hashMap = JSONObject.parseObject(mapJson, HashMap.class); // {id=12, userId=kk}

// json 转实体类
String json = "{\"id\":12,\"userId\":\"kk\"}";
final Answer answer = JSONObject.parseObject(json, Answer.class);  // {id=12, subjectId='null', groupName='null', userAnswer='null', userId='kk'}