将Java字符串转换为CLOB

Question

I have the following table:

The problem is that when I try to use JDBC to insert a String to this field I always get the following error:

java.sql.SQLException: Data size bigger than max size for this type: 6019

what should I do now?

The java code to generate the INSERT is the following:

Connection conn2 = null;
   if(connection==null||connection.isClosed())
   {
    System.out.println("Connection is null");
    conn2 = connectDB();
   }
   //REPLACE is non-standard SQL from MySQL, it's counter part of INSERT IGNORE
   String sql = ""; 
   sql = "INSERT INTO TEST."+tablename+" ("+fields+") VALUES ("+fields.replaceAll("[^,]+", "?")+")";

   System.out.println("SQL: "+sql);
   PreparedStatement pstmt =  conn2.prepareStatement(sql);

   // start parsing
   int event = r.getEventType();
   while (true) {
    // for each wanted element 
    if (event == XMLStreamConstants.START_ELEMENT
      && r.getName().toString().equalsIgnoreCase("row")) {
     System.out.println("Table : "+tablename+" / Row : "+rowCount );
     if (attributeCount == 0)
      attributeCount = r.getAttributeCount();


     //put each parameter to SQL
     int f=1;
     for (String field : fieldsArray){
    String value = r.getAttributeValue("",field);
    if("body".equalsIgnoreCase(field) && value != null) {
         pstmt.setCharacterStream(f++, new CharArrayReader(value.toCharArray()), value.length());
    } else {
         pstmt.setString(f++, value);
    }
 }

     pstmt.addBatch();
     rowCount++;

     if(rowCount%rowspercommit==0){
      System.out.println("Importing at row "+rowCount+" ... ");
      pstmt.executeBatch();
      conn2.commit();
     }
    } // end for each row.

Not sure how the CREATE TABLE is, as someone did that for me

With the current code above, I am now getting this:

Exception in thread "main" java.lang.NullPointerException
    at oracle.jdbc.dbaccess.DBData.clearItem(DBData.java:431)
    at oracle.jdbc.dbaccess.DBDataSetImpl.clearItem(DBDataSetImpl.java:3528)
    at oracle.jdbc.driver.OraclePreparedStatement.checkBindTypes(OraclePreparedStatement.java:3271)
    at oracle.jdbc.driver.OraclePreparedStatement.setStreamItem(OraclePreparedStatement.java:1178)
    at oracle.jdbc.driver.OraclePreparedStatement.setCharacterStream(OraclePreparedStatement.java:3539)
    at XMLDumpImporter.importXMLFile(XMLDumpImporter.java:179)
    at XMLDumpImporter.importXMLFolder(XMLDumpImporter.java:117)
    at XMLDumpImporter.main(XMLDumpImporter.java:48)

at line:

if("body".equalsIgnoreCase(field) && value != null) {
             pstmt.setCharacterStream(f++, new CharArrayReader(value.toCharArray()), value.length());

Which made no total sense as what could possibly be null

Answer 1

It seems that you are using setString instead of setCharacterStream to set value of the clob. If you are using setString then the driver probably converts the value to varchar2 which has size limit of 4000 characters.

Hackety hack:

int fieldIndex = 0;
for(String fieldName : fieldsArray) {
   String value = r.getAttributeValue("",field);
   if(value != null && "body".equalsIgnoreCase(fieldName)) {
     pstmt.setCharacterStream(++fieldIndex, new StringReader(value), value.length());
   } else {
     pstmt.setString(++fieldIndex, value);
   }
}

Relevant documentation:

• setCharacterStream or setClob or setAsciiStream
• StringReader
• CharArrayReader
• ByteArrayInputStream