Java Clob.getCharacterStream方法代碼示例

import java.sql.Clob; //導入方法依賴的package包/類
/**
 * Tests for fix to BUG#1130
 * 
 * @throws Exception
 *             if the test fails
 */
public void testClobTruncate() throws Exception {
    createTable("testClobTruncate", "(field1 TEXT)");
    this.stmt.executeUpdate("INSERT INTO testClobTruncate VALUES ('abcdefg')");

    this.rs = this.stmt.executeQuery("SELECT * FROM testClobTruncate");
    this.rs.next();

    Clob clob = this.rs.getClob(1);
    clob.truncate(3);

    Reader reader = clob.getCharacterStream();
    char[] buf = new char[8];
    int charsRead = reader.read(buf);

    String clobAsString = new String(buf, 0, charsRead);

    assertTrue(clobAsString.equals("abc"));
}
 

import java.sql.Clob; //導入方法依賴的package包/類
/**
 * @see java.sql.PreparedStatement#setClob(int, java.sql.Clob)
 */
@Override
public void setClob(int parameterIndex, Clob x) throws SQLException {
    synchronized (checkClosed().getConnectionMutex()) {

        if (x == null) {
            setNull(parameterIndex, java.sql.Types.BINARY);
        } else {
            BindValue binding = getBinding(parameterIndex, true);
            resetToType(binding, MysqlDefs.FIELD_TYPE_BLOB);

            binding.value = x.getCharacterStream();
            binding.isLongData = true;

            if (this.connection.getUseStreamLengthsInPrepStmts()) {
                binding.bindLength = x.length();
            } else {
                binding.bindLength = -1;
            }
        }
    }
}
 

import java.sql.Clob; //導入方法依賴的package包/類
public static String toStr(Clob clob) {
	StringBuffer sb = new StringBuffer();
	try {
		java.io.Reader is = clob.getCharacterStream();
		BufferedReader br = new BufferedReader(is);
		String s = br.readLine();
		while (s != null) {
			sb.append(s);
			s = br.readLine();
		}
		
	} catch (Exception e) {
		throw new  RuntimeException(e);
	}
	return sb.toString();
}
 

import java.sql.Clob; //導入方法依賴的package包/類
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();

        StringWriter writer = new StringWriter();
        char[] buf = new char[1024];
        int len = 0;
        while ((len = reader.read(buf)) != -1) {
            writer.write(buf, 0, len);
        }
        reader.close();
        
        String text = writer.toString();
        serializer.write(text);
    } catch (SQLException e) {
        throw new IOException("write clob error", e);
    }
}
 

import java.sql.Clob; //導入方法依賴的package包/類
/**
 * @see java.sql.PreparedStatement#setClob(int, java.sql.Clob)
 */
@Override
public void setClob(int parameterIndex, Clob x) throws SQLException {
    synchronized (checkClosed().getConnectionMutex()) {

        if (x == null) {
            setNull(parameterIndex, java.sql.Types.BINARY);
        } else {
            BindValue binding = getBinding(parameterIndex, true);
            setType(binding, MysqlDefs.FIELD_TYPE_BLOB);

            binding.value = x.getCharacterStream();
            binding.isNull = false;
            binding.isLongData = true;

            if (this.connection.getUseStreamLengthsInPrepStmts()) {
                binding.bindLength = x.length();
            } else {
                binding.bindLength = -1;
            }
        }
    }
}
 

import java.sql.Clob; //導入方法依賴的package包/類
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);
    }
}
 

import java.sql.Clob; //導入方法依賴的package包/類
private void setClobForStringParameter(int parameterIndex,
        Clob x) throws SQLException {

    if (x instanceof JDBCClob) {
        setParameter(parameterIndex, ((JDBCClob) x).data());

        return;
    } else if (x == null) {
        setParameter(parameterIndex, null);

        return;
    }
    checkSetParameterIndex(parameterIndex, false);

    final long length = x.length();

    if (length > Integer.MAX_VALUE) {
        String msg = "Max Clob input character length exceeded: " + length;    // NOI18N

        throw Util.sqlException(ErrorCode.JDBC_INPUTSTREAM_ERROR, msg);
    }

    try {
        java.io.Reader  reader = x.getCharacterStream();
        CharArrayWriter writer = new CharArrayWriter(reader, (int) length);

        setParameter(parameterIndex, writer.toString());
    } catch (IOException e) {
        throw Util.sqlException(ErrorCode.SERVER_TRANSFER_CORRUPTED,
                                e.toString());
    }
}
 

import java.sql.Clob; //導入方法依賴的package包/類
public static String ConvertClobToString(StringBuffer sb, Clob clob) throws SQLException, IOException{
	Reader reader = clob.getCharacterStream();
	char[] buffer = new char[(int)clob.length()];
	while(reader.read(buffer) != -1){
		sb.append(buffer);
	}
	return sb.toString();
}
 

import java.sql.Clob; //導入方法依賴的package包/類
@Override
public Reader getClobAsCharacterStream(ResultSet rs, int columnIndex) throws SQLException {
	logger.debug("Returning Oracle CLOB as character stream");
	Clob clob = rs.getClob(columnIndex);
	initializeResourcesBeforeRead(rs.getStatement().getConnection(), clob);
	Reader retVal = (clob != null ? clob.getCharacterStream() : null);
	releaseResourcesAfterRead(rs.getStatement().getConnection(), clob);
	return retVal;
}
 

import java.sql.Clob; //導入方法依賴的package包/類
private void setClobForStringParameter(int parameterIndex,
        Clob x) throws SQLException {

    if (x instanceof JDBCClob) {
        setParameter(parameterIndex, ((JDBCClob) x).data());

        return;
    } else if (x == null) {
        setParameter(parameterIndex, null);

        return;
    }

    final long length = x.length();

    if (length > Integer.MAX_VALUE) {
        String msg = "Max Clob input character length exceeded: " + length;    // NOI18N

        throw JDBCUtil.sqlException(ErrorCode.JDBC_INPUTSTREAM_ERROR, msg);
    }

    try {
        java.io.Reader  reader = x.getCharacterStream();
        CharArrayWriter writer = new CharArrayWriter(reader, (int) length);

        setParameter(parameterIndex, writer.toString());
    } catch (Throwable e) {
        throw JDBCUtil.sqlException(ErrorCode.SERVER_TRANSFER_CORRUPTED,
                                e.toString(), e);
    }
}
 

import java.sql.Clob; //導入方法依賴的package包/類
/**
     * <!-- start generic documentation -->
     * Sets the designated parameter to the given <code>Clob</code> object.
     * The driver converts this to an SQL <code>CLOB</code> value when it
     * sends it to the database. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Previous to 1.7.2, this feature was not supported. <p>
     *
     * Since 1.7.2, setClob is supported.  With 1.7.2, setting Blob objects is
     * limited to those of length less than or equal to Integer.MAX_VALUE.
     * In 1.7.2, setClob(i,x) is rougly equivalent (null and length handling
     * not shown) to: <p>
     *
     * <pre class="JavaCodeExample">
     * <b>setCharacterStream</b>(i, x.<b>getCharacterStream</b>(), (<span class="JavaKeyWord">int</span>) x.<b>length</b>());
     * </pre></div>
     * <!-- end release-specific documentation -->
     * @param i the first parameter is 1, the second is 2, ...
     * @param x a <code>Clob</code> object that maps an SQL <code>CLOB</code>
     *      value
     * @exception SQLException if a database access error occurs
     * @since JDK 1.2 (JDK 1.1.x developers: read the new overview for
     *  jdbcPreparedStatement)
     */
// [email protected] 20030801 - method implemented
//#ifdef JAVA2
    public void setClob(int i, Clob x) throws SQLException {

        if (x instanceof jdbcClob) {
            setParameter(i, ((jdbcClob) x).data);

            return;
        } else if (x == null) {
            setParameter(i, null);

            return;
        }

        checkSetParameterIndex(i, false);

        final long length = x.length();

        if (length > Integer.MAX_VALUE) {
            String msg = "Max Clob input character length exceeded: " + length;

            throw Util.sqlException(Trace.INPUTSTREAM_ERROR, msg);
        }

        java.io.Reader     reader = x.getCharacterStream();
        final StringBuffer sb     = new StringBuffer();
        final int          size   = 2048;
        final char[]       buff   = new char[size];

        try {
            for (int left = (int) length; left > 0; ) {
                final int read = reader.read(buff, 0, left > size ? size
                                                                  : left);

                if (read == -1) {
                    break;
                }

                sb.append(buff, 0, read);

                left -= read;
            }
        } catch (IOException e) {
            throw Util.sqlException(Trace.TRANSFER_CORRUPTED, e.toString());
        }

        setParameter(i, sb.toString());
    }
 

import java.sql.Clob; //導入方法依賴的package包/類
/**
 * Actually read a ClobRef instance from the ResultSet and materialize
 * the data either inline or to a file.
 *
 * @param colNum the column of the ResultSet's current row to read.
 * @param r the ResultSet to read from.
 * @return a ClobRef encapsulating the data in this field.
 * @throws IOException if an error occurs writing to the FileSystem.
 * @throws SQLException if an error occurs reading from the database.
 */
public com.cloudera.sqoop.lib.ClobRef readClobRef(int colNum, ResultSet r)
    throws IOException, InterruptedException, SQLException {

  long maxInlineLobLen = conf.getLong(
      MAX_INLINE_LOB_LEN_KEY,
      DEFAULT_MAX_LOB_LENGTH);

  Clob c = r.getClob(colNum);
  if (null == c) {
    return null;
  } else if (c.length() > maxInlineLobLen) {
    // Deserialize large CLOB into separate file.
    long len = c.length();
    LobFile.Writer lobWriter = getClobWriter();

    long recordOffset = lobWriter.tell();
    Reader reader = null;
    Writer w = lobWriter.writeClobRecord(len);
    try {
      reader = c.getCharacterStream();
      copyAll(reader, w);
    } finally {
      if (null != w) {
        w.close();
      }

      if (null != reader) {
        reader.close();
      }

      // Mark the record as finished.
      lobWriter.finishRecord();
    }

    return new com.cloudera.sqoop.lib.ClobRef(
        getRelativePath(lobWriter), recordOffset, len);
  } else {
    // This is a 1-based array.
    return new com.cloudera.sqoop.lib.ClobRef(
        c.getSubString(1, (int) c.length()));
  }
}