java List轉換爲字符串的幾種方法

方法一

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);  
}  

方法二

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();  
}  

方法三

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();  
}  

方法四

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

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

    public String get() {  
        String result = next;  
        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();  
}

方法五

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

總結：方法五在實際應用中最多，因爲它已經被封裝好了，速度也很快