Oracle处理CLOB超过4000入库问题 （2）

         接上一篇转载的Oracle处理CLOB超过4000入库问题，同事用我的写的代码，说仍出现问题，后面写了另一种方法，在这里做一个记录，以便以后学习。

先把需求简要提出来：

public String toInsertSql(){
String sql="insert into TB_NEWS ("+
"title,"+
"publictime,"+
"source,"+
"abstract,"+
"content,"+
"url,"+
"infodate,"+
"author,"+
"hits,"+
"expand,"+
"createtime,"+
"modifytime"+
") "+
"values (";
if(this.getTitle() == null){
sql += "'',";
}else{
sql += "'"+this.getTitle().replaceAll("'", "")+"'"+",";
}
if(this.getPublictime() == null){
sql += "'',";
}else{
sql += "'"+this.getPublictime().replaceAll("'", "")+"'"+",";
}
if(this.getSource() == null){
sql += "'',";
}else{
sql += "'"+this.getSource().replaceAll("'", "")+"'"+",";
}
if(this.getAbstracts() == null){
sql += "'',";
}else{
sql += "'"+this.getAbstracts().replaceAll("'", "")+"'"+",";
}
if(this.getContent() == null){
sql += "'',";
}else{
// sql += "'"+this.getContent().replaceAll("'", "")+"'"+",";
sql += "?,";
}
if(this.getUrl() == null){
sql += "'',";
}else{
sql += "'"+this.getUrl().replaceAll("'", "")+"'"+",";
}
if(this.getInfodate() == null){
sql += "'',";
}else{
sql += "'"+this.getInfodate().replaceAll("'", "")+"'"+",";
}
if(this.getAuthor() == null){
sql += "'',";
}else{
sql += "'"+this.getAuthor().replaceAll("'", "")+"'"+",";
}
if(this.getHits() == null){
sql += "'',";
}else{
sql += "'"+this.getHits().replaceAll("'", "")+"'"+",";
}
if(this.getExpand() == null){
sql += "'',";
}else{
sql += "'"+this.getExpand().replaceAll("'", "")+"'"+",";
}
if(this.getCreatetime() == null){
sql += "'',";
}else{
sql += "to_date('"+this.getCreatetime()+"','yyyymmdd HH24:mi:ss'),"; //to_date('20140214','yyyymmdd')
}
if(this.getModifytime() == null){
sql += "''";
}else{
sql += "to_date('"+this.getCreatetime()+",'yyyymmdd HH24:mi:ss'),";
}

sql += ")";
return sql;
}这是一个sql语句，content为大数据字段，content中注释的为方法一种使用的sql，没有注释的是方法二中使用的sql

方法一：参考上一篇转载的文章，代码如下：

public static void insert(String sql,String url,String content) {

conn = getConnection();

try {
st = conn.createStatement(); // 创建用于执行静态sql语句的Statement对象
//st.executeUpdate(sql); // 执行插入操作的sql语句，并返回插入数据的个数
/**
* clob数据太长超过4000，如下处理
* 1、插入一个空对象empty_clob()
* 2、锁定数据行进行更新，注意“for update”语句
*/
//1、插入一个空对象empty_clob()
sql = sql.replace("'"+content+"'", "empty_clob()");
st.executeUpdate(sql);

//2、锁定数据行进行更新，注意“for update”语句
String sql2 = "select CONTENT from TB_NEWS where url='"+url+"' for update";
//System.out.println(sql2);
ResultSet rs = st.executeQuery(sql2);

if(rs.next()){

//得到java.sql.Clob对象后强制转换为oracle.sql.CLOB
oracle.sql.CLOB clob = (CLOB) rs.getClob("content");
outStream = clob.getCharacterOutputStream();
//data是传入的字符串，定义：String data
char[] c = content.toCharArray();

outStream.write(c, 0, c.length);

}
outStream.flush();
conn.commit();
} catch (Exception e) {
if(e.getMessage().contains("唯一键约束"))
;
else{
logger.error("插入数据库出错，sql语句："+sql);
e.printStackTrace();
}
} finally{
try {
if(outStream!=null){outStream.close();}
if(rs!=null){rs.close();}
if(st!=null){st.close();}
if(conn != null){conn.close();}
} catch (Exception e) {
e.printStackTrace();
}
}

}

方法二：使用setCharacterStream来处理大数据插入问题，代码如下：
public static void insert(String sql,String content) {
conn = getConnection();
PreparedStatement statement = null;
try {
st = conn.createStatement(); // 创建用于执行静态sql语句的Statement对象
statement=conn.prepareStatement(sql);
Reader reader=new StringReader(content);
statement.setCharacterStream(1, reader,content.length());
statement.executeUpdate();
conn.commit();
} catch (Exception e) {
logger.error("插入数据库出错，sql语句："+sql);
e.printStackTrace();
} finally{
try {
if(statement!=null){conn.close();}
if(conn != null){conn.close();}
} catch (Exception e) {
e.printStackTrace();
}
}

}