java List转换为字符串的几种方法

public String listToString(List list, char separator) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < list.size(); i++) {
sb.append(list.get(i)).append(separator);
}
return list.isEmpty()?"":sb.toString().substring(0, sb.toString().length() - 1);
}

public String listToString2(List list, char separator) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < list.size(); i++) {
if (i == list.size() - 1) {
sb.append(list.get(i));
} else {
sb.append(list.get(i));
sb.append(separator);
}
}
return sb.toString();
}

public String listToString3(List list, char separator) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < list.size(); i++) {
sb.append(list.get(i));
if (i < list.size() - 1) {
sb.append(separator);
}
}
return sb.toString();
}

public class Separator {
private String next = "";
private String separator;

public Separator(String separator) {
this.separator = separator;
}

public String get() {
String result = next;

4000
next = separator;
return result;
}
}

public String listToString4(List<String> list, Separator separator) {
StringBuilder sb = new StringBuilder();
for (String s : list) {
if (s != null && !"".equals(s)) {
sb.append(separator.get()).append(s);
}
}
return sb.toString();
}

public String listToString5(List list, char separator) {
return org.apache.commons.lang.StringUtils.join(list.toArray(),separator);
}