List集合的去重

private boolean parseBookLanguage(final String jsonstr, final String orgGid) throws Exception {
//解析一个json串
JSONObject obj = JSONObject.parseObject(jsonstr);
// 返回true
if (obj.getBooleanValue(“RESULT”)) {
JSONArray arr = obj.getJSONArray(“DATA”);
开始考虑到用Set集合去重但是set集合会将后面添加的对象删掉保存的是原来的对象
CopyOnWriteArraySet和CopyOnWriteArrayList是一个安全线程的集合
// final Setset=new CopyOnWriteArraySet<>();
final List data = new CopyOnWriteArrayList<>();
for (int i = 0; i < arr.size(); i++) {
JSONObject langDicObject = arr.getJSONObject(i);
String langCodeSrc = langDicObject.getString(“LANGCODE”);
String langCode = IdGenerator.encodeBase64(langCodeSrc, orgGid);
OrgBookLangDicBO bookLangDicBO = new OrgBookLangDicBO(langCode, langDicObject.getString(“LANGNAME”),orgGid, langCodeSrc);
// 添加之前先查询之前集合是否包含这个对象
if (data.contains(bookLangDicBO)) {
data.remove(bookLangDicBO);//remove会将原来的移除
}
data.add(bookLangDicBO);
}
// 备份
boolean flag = dataTransferDAO.backupBookLanguage(orgGid);
// 删除
flag = dataTransferDAO.deleteBookLanguage(orgGid);
// 添加
flag = dataTransferDAO.insertBookLanguage(data);

        return flag;
    } else {
        // 返回的false
        throw new Exception(obj.toJSONString());
    }

}

//但是这样处理会比较繁琐直接在循环获取对象的时候从后往前取对象避免就可以不用再替换了
private boolean parseBookLanguage(final String jsonstr, final String orgGid) throws Exception {
//解析一个json串
JSONObject obj = JSONObject.parseObject(jsonstr);
// 返回true
if (obj.getBooleanValue(“RESULT”)) {
JSONArray arr = obj.getJSONArray(“DATA”);

    final Set<OrgBookLangDicBO>set=new CopyOnWriteArraySet<>();
//  final List<OrgBookLangDicBO> data = new CopyOnWriteArrayList<>();
        for (int i = arr.size()-1; i >=0; i--) {
            JSONObject langDicObject = arr.getJSONObject(i);
            String langCodeSrc = langDicObject.getString("LANGCODE");
            String langCode = IdGenerator.encodeBase64(langCodeSrc, orgGid);
    OrgBookLangDicBO bookLangDicBO = new OrgBookLangDicBO(langCode,       langDicObject.getString("LANGNAME"),orgGid, langCodeSrc);
        // 添加之前先查询之前集合是否包含这个对象
    set.add(bookLangDicBO);
        // 备份
        boolean flag = dataTransferDAO.backupBookLanguage(orgGid);
        // 删除
        flag = dataTransferDAO.deleteBookLanguage(orgGid);
        // 添加
        flag = dataTransferDAO.insertBookLanguage(data);

        return flag;
    } else {
        // 返回的false
        throw new Exception(obj.toJSONString());
    }

}

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