Java 如果可能，将列表转换为静态字符串

我正在尝试将我的头绕在列表上我有一个动态创建的数组列表，选择了一些标记，我想转换这些标记，将元素分开，并在每个元素之间放置一个%的位置，这样我就可以在http调用中使用新的字符串

创建我的新列表：

public List<String> selected_tags = new ArrayList<String>();

---

事实上，你应该有

StringBuilder sb = new StringBuilder();
if(selected_tags.size() > 0) {
    sb.append(selected_tags.get(0);
    for(int i = 1 ; i < selected_tags.size(); i++) {
        sb.append("%");
        sb.append(selected_tags.get(i));
    }
}
return sb.toString();

---

bool first=true不是吗？

HttpGet httpPost = new HttpGet("http://www.mywebsite.com/scripts/getData.php?tags="+ BROKEN DOWN LIST<STRING>);

HttpGet httpPost = new HttpGet("http://www.mywebsite.com/scripts/getData.php?tags=tag1%tag2%tag3);

StringBuilder s = new StringBuilder();
boolean first = true;   

for (String tag : selected_tags)  {
    if (!first)
        s.append("%");
    else
        first = false;

    s.append(tag);
}

String myUrlString = "tags=" + s.toString();

StringBuilder sb = new StringBuilder();
for (String tag : selected_tags) {
    sb.append("%").append(tag);
}
sb.replace(0,1,"tags=");

StringBuilder result = new StringBuilder();

String prepend = "tags=";
for( String tag : selected_tags ){
    result.append(prepend).append(tag);
    prepend = "%";
}

String resultString = result.toString();

StringBuilder sb = new StringBuilder();
if(selected_tags.size() > 0) {
    sb.append(selected_tags.get(0);
    for(int i = 1 ; i < selected_tags.size(); i++) {
        sb.append("%");
        sb.append(selected_tags.get(i));
    }
}
return sb.toString();