原文链接：http://blog.csdn.net/qq7342272/article/details/6830907#comments
调试时出现bug，在String中包含list嵌套或map嵌套时会出现字符串下标越界异常，原因是split分割时会出现""字符串，此时引用str.charAt(0)会抛出该异常，如图：
优化代码，经调试暂时解决String中2层嵌套list转换，如下：
1 package test; 2 3 import java.util.ArrayList; 4 import java.util.HashMap; 5 import java.util.List; 6 import java.util.Map; 7 8 public class CopyOfStringUtil { 9 10 /** 11 * 定义分割常量 12 * #用于list中每个元素间的分割 13 * |用于map中每一个kv对间的分割 14 * =用于map中key与value间的分割 15 */ 16 private static final String SEP1 = ","; 17 private static final String SEP2 = "|"; 18 private static final String SEP3 = "="; 19 20 /** 21 * List转换String 22 * 23 * @param list 24 * :需要转换的List 25 * @return String转换后的字符串 26 */ 27 public static String ListToString(List<?> list) { 28 StringBuffer sb = new StringBuffer(); 29 if (list != null && list.size() > 0) { 30 for (int i = 0; i < list.size(); i++) { 31 if (list.get(i) == null || list.get(i) == "") { 32 continue; 33 } 34 // 如果值是list类型则调用自己 35 if (list.get(i) instanceof List) { 36 sb.append(ListToString((List<?>) list.get(i))); 37 sb.append(SEP1); 38 } else if (list.get(i) instanceof Map) { 39 sb.append(MapToString((Map<?, ?>) list.get(i))); 40 sb.append(SEP1); 41 } else { 42 sb.append(list.get(i)); 43 sb.append(SEP1); 44 } 45 } 46 } 47 return "L" + sb.toString(); 48 } 49 50 /** 51 * Map转换String 52 * 53 * @param map 54 * :需要转换的Map 55 * @return String转换后的字符串 56 */ 57 public static String MapToString(Map<?, ?> map) { 58 StringBuffer sb = new StringBuffer(); 59 // 遍历map 60 for (Object obj : map.keySet()) { 61 if (obj == null) { 62 continue; 63 } 64 Object key = obj; 65 Object value = map.get(key); 66 if (value instanceof List<?>) { 67 sb.append(key.toString() + SEP1 + ListToString((List<?>) value)); 68 sb.append(SEP2); 69 } else if (value instanceof Map<?, ?>) { 70 sb.append(key.toString() + SEP1 + MapToString((Map<?, ?>) value)); 71 sb.append(SEP2); 72 } else { 73 sb.append(key.toString() + SEP3 + value.toString()); 74 sb.append(SEP2); 75 } 76 } 77 return "M" + sb.toString(); 78 } 79 80 /** 81 * String转换Map 82 * 83 * @param mapText 84 * :需要转换的字符串 85 * @return Map<?,?> 86 */ 87 public static Map<String, Object> StringToMap(String mapText) { 88 89 if (mapText == null || mapText.equals("")) { 90 return null; 91 } 92 mapText = mapText.substring(1); 93 94 Map<String, Object> map = new HashMap<String, Object>(); 95 String[] text = mapText.split("\" + SEP2); // 转换为数组 96 for (String str : text) { 97 String[] keyText = str.split(SEP3); // 转换key与value的数组 98 if (keyText.length < 1) { 99 continue;100 }101 String key = keyText[0]; // key102 String value = keyText[1]; // value103 if (value.charAt(0) == 'M') {104 Map<?, ?> map1 = StringToMap(value);105 map.put(key, map1);106 } else if (value.charAt(0) == 'L') {107 List<?> list = StringToList(value);108 map.put(key, list);109 } else {110 map.put(key, value);111 }112 }113 return map;114 }115 116 /**117 * String转换List118 * 119 * @param listText120 * :需要转换的文本121 * @return List<?>122 */123 public static List<Object> StringToList(String listText) {124 if (listText == null || listText.equals("")) {125 return null;126 }127 listText = listText.substring(1);128 129 List<Object> list = new ArrayList<Object>();130 String[] text = listText.split("\" + SEP1);131 String listStr = "";132 boolean flag = false;133 for (String str : text) {134 if (!str.equals("")) {135 if (str.charAt(0) == 'M') {136 Map<?, ?> map = StringToMap(str);137 list.add(map);138 } else if (str.charAt(0) == 'L' || flag) {139 flag = true;140 listStr += str + SEP1;141 } else {142 list.add(str);143 }144 }145 if (str.equals("")) {146 flag = false;147 List<?> lists = StringToList(listStr);148 list.add(lists);149 }150 }151 return list;152 }153 154 }测试代码如下：
1 package test; 2 3 import java.util.ArrayList; 4 import java.util.HashMap; 5 import java.util.List; 6 import java.util.Map; 7 8 public class StringUtilTest { 9 10 List<Object> list = new ArrayList<Object>();//外层list11 List<Object> innerList = new ArrayList<Object>();//内层嵌套list12 Map<String, Object> map = new HashMap<String, Object>();13 String listText, mapText;14 15 /**16 * 测试数据初始化17 */18 public StringUtilTest() {19 innerList.add("innerlist1");20 innerList.add("innerlist2");21 list.add(innerList);22 list.add("out1");23 list.add("out2");24 25 map.put("innermap1", "v1");26 map.put("innermap2", "v2");27 28 listText = "LLinnerlist1,innerlist2,,out1,out2,";//list字符串源29 30 mapText = "Minnermap2=v2|innermap1=v1|";//map字符串源31 }32 33 public static void main(String[] args) {34 StringUtilTest test = new StringUtilTest();35 36 String ls = test.testListToString();37 System.out.println(ls);38 39 String ms = test.testMapToString();40 System.out.println(ms);41 42 List<?> list = test.testStringToList();43 System.out.println(list);44 45 Map<?, ?> map = test.testStringToMap();46 System.out.println(map);47 }48 49 public String testListToString() {50 return CopyOfStringUtil.ListToString(list);51 }52 53 public String testMapToString() {54 return CopyOfStringUtil.MapToString(map);55 }56 57 public List<?> testStringToList() {58 return CopyOfStringUtil.StringToList(listText);59 }60 61 public Map<?, ?> testStringToMap() {62 return CopyOfStringUtil.StringToMap(mapText);63 }64 65 }测试结果，满足2层嵌套list：