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  • Java List 转 String

    JAVA中List转换String,String转换List,Map转换String,String转换Map之间的转换工具类(调优)
    https://www.cnblogs.com/cn-wxw/p/6684280.html
    https://blog.csdn.net/yywusuoweile/article/details/50315377
    https://blog.csdn.net/benjaminlee1/article/details/72860845

    import java.util.ArrayList;
    import java.util.List;
    
    public class Main {
    
        public static void main(String[] args) {
            List<String> mList = new ArrayList<>();
            mList.add("s1");
            mList.add("s2");
            mList.add("s3");
            // // method1: In Java 8 ~ String.join(..)
            // String mListStr = String.join(",", mList);
            // String mListStr = listToString(mList);
            String mListStr = listToString2(mList);
            System.out.println("mListStr = " + mListStr);
        }
    
        /**
        * for all jdk version
        * @param mList
        * @return
        */
        public static String listToString(List<String> mList) {
            String convertedListStr = "";
            if (null != mList && mList.size() > 0) {
                String[] mListArray = mList.toArray(new String[mList.size()]);
                for (int i = 0; i < mListArray.length; i++) {
                if (i < mListArray.length - 1) {
                    convertedListStr += mListArray[i] + ",";
                } else {
                    convertedListStr += mListArray[i];
                }
                }
                return convertedListStr;
            } else return "List is null!!!";
        }
    
        /**
        * for jdk <= java 7
        * @param mList
        * @return
        */
        // 采用Stringbuilder.append()的方式追加
        public static String listToString2(List<String> mList) {
            final String SEPARATOR = ",";
            // mList = Arrays.asList("AAA", "BBB", "CCC");
            StringBuilder sb = new StringBuilder();
            String convertedListStr = "";
            if (null != mList && mList.size() > 0) {
                for (String item : mList) {
                    sb.append(item);
                    sb.append(SEPARATOR);
                }
                convertedListStr = sb.toString();
                convertedListStr = convertedListStr.substring(0, convertedListStr.length()
                - SEPARATOR.length());
                return convertedListStr;
            } else return "List is null!!!";
        }
    }

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  • 原文地址:https://www.cnblogs.com/bluestorm/p/8811077.html
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