Question

oracle数据库CLOB类型怎么转换为String

oracle数据库中的字段类型是CLOB，而JavaBean中定义的字段是String，在java中往外读取数据的时候，打印的数据时类似于内存地址值一样的字符串，请问怎么转换啊？

Answer 1

给你段参考代码，读取clob数据

import java.io.InputStream;
import java.io.Reader;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

public class TestClobOut {
public static void main(String args[]){
String data;
Reader inStream=null;
//获得数据库连接
Connection con = ConnectionFactory.getConnection();//ConnectionFactory类是另外定义的，不必纠结
con.setAutoCommit(false);
Statement st = con.createStatement();
//不需要“for update”
ResultSet rs = st.executeQuery("select CLOBATTR from TESTCLOB where ID=1");
if (rs.next())
{
java.sql.Clob clob = rs.getClob("CLOBATTR");
inStream = clob.getCharacterStream();
char[] c = new char[(int) clob.length()];
inStream.read(c);
//data是读出并需要返回的数据，类型是String
data = new String(c);
inStream.close();
}
inStream.close();
con.commit();
con.close();
}
}

Answer 2

1. 给你段参考代码，读取clob数据
   
   import java.io.InputStream;
   import java.io.Reader;
   import java.sql.Connection;
   import java.sql.ResultSet;
   import java.sql.Statement;
   public class TestClobOut {
   public static void main(String args[]){
   String data;
   Reader inStream=null;
   //获得数据库连接

2. Connection con = ConnectionFactory.getConnection();//ConnectionFactory类是另外定义的，不必纠结
   con.setAutoCommit(false);
   Statement st = con.createStatement();
   //不需要“for update”
   ResultSet rs = st.executeQuery("select CLOBATTR from TESTCLOB where ID=1");
   if (rs.next())
   {clob 转换 String (传入 clob 类型的 obj 对象)
   public static String getClob2String(Object obj) {
   String str = "";
   try {
   CLOB clob = (CLOB) obj;
   if (clob == null || clob.length() == 0) {
   str = "";
   } else {
   long clen = clob.length();
   char clobArray[] = new char[(int) clen];
   int readednum = clob.getChars(1, (int) clen, clobArray);
   StringBuffer sb = new StringBuffer();
   sb.append(clobArray);
   str = sb.toString();
   }
   } catch (SQLException e) {
   e.printStackTrace();
   }
   return str;
   }
   java.sql.Clob clob = rs.getClob("CLOBATTR");
   inStream = clob.getCharacterStream();
   char[] c = new char[(int) clob.length()];
   inStream.read(c);
   //data是读出并需要返回的数据，类型是String
   data = new String(c);
   inStream.close();
   }
   inStream.close();
   con.commit();
   con.close();
   }
   }