一个生成json字符串的类

public class UserProjWorkloadQueryTreeNodeUtil {

    @SuppressWarnings("unchecked")
    public static String getJsonString(List<UserProjWorkloadQueryTreeNode> list) {
        if (list == null || list.isEmpty()) {
            return "";
        }
        StringBuffer sb = new StringBuffer();
        if (list != null && !list.isEmpty()) {
            boolean first = true;
            for (UserProjWorkloadQueryTreeNode node : list) {
                if (first) {
                    sb.append("[");
                    first = false;
                } else {
                    sb.append(",");
                }
                if (node.isLeaf()) {
                    sb.append("{");
                    getQueryTreeNodeData(sb, node);
                    sb.append("}");
                } else {
                    sb.append("{");
                    getQueryTreeNodeData(sb, node);
                    sb.append(",children:");
                    sb.append(getJsonString(node.getChildren()));
                    sb.append("}");
                }
            }
            sb.append("]");
        }
        return sb.toString();
    }

    /**
     * 将本节点的信息写到sb中.
     * 
     * @param sb
     * @param node
     */
    private static void getQueryTreeNodeData(StringBuffer sb, UserProjWorkloadQueryTreeNode node) {
        List<WorkloadRecord> attributes = node.getAttributes();
        for (WorkloadRecord record : attributes) {
            sb.append("\"").append(record.getRecordTitle()).append("\":\"").append(record.getDisplayString()).append(
                    "\",");
        }
        sb.append("\"id\":").append("\"").append(node.getId()).append("\",");
        sb.append("\"entityId\":").append(node.getEntityId()).append(",");
        sb.append("\"uiProvider\":").append("\"").append(node.getUiProvider()).append("\",");
        sb.append("\"leaf\":").append(node.isLeaf()).append(",");
        sb.append("\"task\":").append("\"").append(node.getIconCls()).append("\",");
        sb.append("\"href\":").append("\"").append(node.getHref()).append("\",");
        sb.append("\"type\":").append("\"").append(node.getType()).append("\",");
        sb.append("\"hrefTarget\":").append("\"").append(node.getHrefTarget()).append("\",");
        sb.append("\"singleClickExpand\":").append(node.isSingleClickExpand());
    }

}