content: package com.alibaba.fastjson.serializer;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.lang.reflect.Type;
  import java.sql.Clob;
  import java.sql.SQLException;
  
  import com.alibaba.fastjson.JSONException;
  
  public class ClobSerializer implements ObjectSerializer {
  
      public final static ClobSerializer instance = new ClobSerializer();
  
      public void write(JSONSerializer serializer, Object object, Object fieldName, Type fieldType, int features) throws IOException {
          try {
              if (object == null) {
                  serializer.writeNull();
                  return;
              }
              
              Clob clob = (Clob) object;
              Reader reader = clob.getCharacterStream();
  
              StringBuilder buf = new StringBuilder();
              
              try {
                  char[] chars = new char[2048];
                  for (;;) {
                      int len = reader.read(chars, 0, chars.length);
                      if (len < 0) {
                          break;
                      }
                      buf.append(chars, 0, len);
                  }
              } catch(Exception ex) {
                  throw new JSONException("read string from reader error", ex);
              }
              
              String text = buf.toString();
              reader.close();
              serializer.write(text);
          } catch (SQLException e) {
              throw new IOException("write clob error", e);
          }
      }
  
  }
  