org.apache.commons.dbutils.wrappers.SqlNullCheckedResultSet Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jsqlbox Show documentation
Show all versions of jsqlbox Show documentation
jSqlBox is a full function DAO tool
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.dbutils.wrappers;
import java.io.InputStream;
import java.io.Reader;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.net.URL;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.Date;
import java.sql.Ref;
import java.sql.ResultSet;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.dbutils.ProxyFactory;
/**
* Decorates a ResultSet with checks for a SQL NULL value on each
* getXXX method. If a column value obtained by a
* getXXX method is not SQL NULL, the column value is returned. If
* the column value is SQL null, an alternate value is returned. The alternate
* value defaults to the Java null value, which can be overridden
* for instances of the class.
*
*
* Usage example:
*
*
* Connection conn = // somehow get a connection
* Statement stmt = conn.createStatement();
* ResultSet rs = stmt.executeQuery("SELECT col1, col2 FROM table1");
*
* // Wrap the result set for SQL NULL checking
* SqlNullCheckedResultSet wrapper = new SqlNullCheckedResultSet(rs);
* wrapper.setNullString("---N/A---"); // Set null string
* wrapper.setNullInt(-999); // Set null integer
* rs = ProxyFactory.instance().createResultSet(wrapper);
*
* while (rs.next()) {
* // If col1 is SQL NULL, value returned will be "---N/A---"
* String col1 = rs.getString("col1");
* // If col2 is SQL NULL, value returned will be -999
* int col2 = rs.getInt("col2");
* }
* rs.close();
*
*
* </p>
* Unlike some other classes in DbUtils, this class is NOT thread-safe.
*/
public class SqlNullCheckedResultSet implements InvocationHandler {
/**
* Maps normal method names (ie. "getBigDecimal") to the corresponding null
* Method object (ie. getNullBigDecimal).
*/
private static final Map nullMethods = new HashMap();
/**
* The {@code getNull} string prefix.
* @since 1.4
*/
private static final String GET_NULL_PREFIX = "getNull";
static {
Method[] methods = SqlNullCheckedResultSet.class.getMethods();
for (int i = 0; i < methods.length; i++) {
String methodName = methods[i].getName();
if (methodName.startsWith(GET_NULL_PREFIX)) {
String normalName = "get" + methodName.substring(GET_NULL_PREFIX.length());
nullMethods.put(normalName, methods[i]);
}
}
}
/**
* The factory to create proxies with.
*/
private static final ProxyFactory factory = ProxyFactory.instance();
/**
* Wraps the ResultSet in an instance of this class. This is
* equivalent to:
*
* ProxyFactory.instance().createResultSet(new SqlNullCheckedResultSet(rs));
*
*
* @param rs The ResultSet to wrap.
* @return wrapped ResultSet
*/
public static ResultSet wrap(ResultSet rs) {
return factory.createResultSet(new SqlNullCheckedResultSet(rs));
}
private InputStream nullAsciiStream = null;
private BigDecimal nullBigDecimal = null;
private InputStream nullBinaryStream = null;
private Blob nullBlob = null;
private boolean nullBoolean = false;
private byte nullByte = 0;
private byte[] nullBytes = null;
private Reader nullCharacterStream = null;
private Clob nullClob = null;
private Date nullDate = null;
private double nullDouble = 0.0;
private float nullFloat = 0.0f;
private int nullInt = 0;
private long nullLong = 0;
private Object nullObject = null;
private Ref nullRef = null;
private short nullShort = 0;
private String nullString = null;
private Time nullTime = null;
private Timestamp nullTimestamp = null;
private URL nullURL = null;
/**
* The wrapped result.
*/
private final ResultSet rs;
/**
* Constructs a new instance of
* SqlNullCheckedResultSet
* to wrap the specified ResultSet.
* @param rs ResultSet to wrap
*/
public SqlNullCheckedResultSet(ResultSet rs) {
super();
this.rs = rs;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getAsciiStream method.
*
* @return the value
*/
public InputStream getNullAsciiStream() {
return this.nullAsciiStream;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getBigDecimal method.
*
* @return the value
*/
public BigDecimal getNullBigDecimal() {
return this.nullBigDecimal;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getBinaryStream method.
*
* @return the value
*/
public InputStream getNullBinaryStream() {
return this.nullBinaryStream;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getBlob method.
*
* @return the value
*/
public Blob getNullBlob() {
return this.nullBlob;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getBoolean method.
*
* @return the value
*/
public boolean getNullBoolean() {
return this.nullBoolean;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getByte method.
*
* @return the value
*/
public byte getNullByte() {
return this.nullByte;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getBytes method.
*
* @return the value
*/
public byte[] getNullBytes() {
if (this.nullBytes == null) {
return null;
}
byte[] copy = new byte[this.nullBytes.length];
System.arraycopy(this.nullBytes, 0, copy, 0, this.nullBytes.length);
return copy;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getCharacterStream method.
*
* @return the value
*/
public Reader getNullCharacterStream() {
return this.nullCharacterStream;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getClob method.
*
* @return the value
*/
public Clob getNullClob() {
return this.nullClob;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getDate method.
*
* @return the value
*/
public Date getNullDate() {
return this.nullDate != null ? new Date(this.nullDate.getTime()) : null;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getDouble method.
*
* @return the value
*/
public double getNullDouble() {
return this.nullDouble;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getFloat method.
*
* @return the value
*/
public float getNullFloat() {
return this.nullFloat;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getInt method.
*
* @return the value
*/
public int getNullInt() {
return this.nullInt;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getLong method.
*
* @return the value
*/
public long getNullLong() {
return this.nullLong;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getObject method.
*
* @return the value
*/
public Object getNullObject() {
return this.nullObject;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getRef method.
*
* @return the value
*/
public Ref getNullRef() {
return this.nullRef;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getShort method.
*
* @return the value
*/
public short getNullShort() {
return this.nullShort;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getString method.
*
* @return the value
*/
public String getNullString() {
return this.nullString;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getTime method.
*
* @return the value
*/
public Time getNullTime() {
return this.nullTime;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getTimestamp method.
*
* @return the value
*/
public Timestamp getNullTimestamp() {
return this.nullTimestamp != null ? new Timestamp(this.nullTimestamp.getTime()) : null;
}
/**
* Returns the value when a SQL null is encountered as the result of
* invoking a getURL method.
*
* @return the value
*/
public URL getNullURL() {
return this.nullURL;
}
/**
* Intercepts calls to get* methods and calls the appropriate
* getNull* method if the ResultSet returned
* null.
*
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])
* @param proxy Not used; all method calls go to the internal result set
* @param method The method to invoke on the result set
* @param args The arguments to pass to the result set
* @return null checked result
* @throws Throwable error
*/
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
Object result = method.invoke(this.rs, args);
Method nullMethod = nullMethods.get(method.getName());
// Check nullMethod != null first so that we don't call wasNull()
// before a true getter method was invoked on the ResultSet.
return (nullMethod != null && this.rs.wasNull())
? nullMethod.invoke(this, (Object[]) null)
: result;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getAsciiStream method.
*
* @param nullAsciiStream the value
*/
public void setNullAsciiStream(InputStream nullAsciiStream) {
this.nullAsciiStream = nullAsciiStream;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getBigDecimal method.
*
* @param nullBigDecimal the value
*/
public void setNullBigDecimal(BigDecimal nullBigDecimal) {
this.nullBigDecimal = nullBigDecimal;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getBinaryStream method.
*
* @param nullBinaryStream the value
*/
public void setNullBinaryStream(InputStream nullBinaryStream) {
this.nullBinaryStream = nullBinaryStream;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getBlob method.
*
* @param nullBlob the value
*/
public void setNullBlob(Blob nullBlob) {
this.nullBlob = nullBlob;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getBoolean method.
*
* @param nullBoolean the value
*/
public void setNullBoolean(boolean nullBoolean) {
this.nullBoolean = nullBoolean;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getByte method.
*
* @param nullByte the value
*/
public void setNullByte(byte nullByte) {
this.nullByte = nullByte;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getBytes method.
*
* @param nullBytes the value
*/
public void setNullBytes(byte[] nullBytes) {
byte[] copy = new byte[nullBytes.length];
System.arraycopy(nullBytes, 0, copy, 0, nullBytes.length);
this.nullBytes = copy;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getCharacterStream method.
*
* @param nullCharacterStream the value
*/
public void setNullCharacterStream(Reader nullCharacterStream) {
this.nullCharacterStream = nullCharacterStream;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getClob method.
*
* @param nullClob the value
*/
public void setNullClob(Clob nullClob) {
this.nullClob = nullClob;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getDate method.
*
* @param nullDate the value
*/
public void setNullDate(Date nullDate) {
this.nullDate = nullDate != null ? new Date(nullDate.getTime()) : null;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getDouble method.
*
* @param nullDouble the value
*/
public void setNullDouble(double nullDouble) {
this.nullDouble = nullDouble;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getFloat method.
*
* @param nullFloat the value
*/
public void setNullFloat(float nullFloat) {
this.nullFloat = nullFloat;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getInt method.
*
* @param nullInt the value
*/
public void setNullInt(int nullInt) {
this.nullInt = nullInt;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getLong method.
*
* @param nullLong the value
*/
public void setNullLong(long nullLong) {
this.nullLong = nullLong;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getObject method.
*
* @param nullObject the value
*/
public void setNullObject(Object nullObject) {
this.nullObject = nullObject;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getRef method.
*
* @param nullRef the value
*/
public void setNullRef(Ref nullRef) {
this.nullRef = nullRef;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getShort method.
*
* @param nullShort the value
*/
public void setNullShort(short nullShort) {
this.nullShort = nullShort;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getString method.
*
* @param nullString the value
*/
public void setNullString(String nullString) {
this.nullString = nullString;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getTime method.
*
* @param nullTime the value
*/
public void setNullTime(Time nullTime) {
this.nullTime = nullTime;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getTimestamp method.
*
* @param nullTimestamp the value
*/
public void setNullTimestamp(Timestamp nullTimestamp) {
this.nullTimestamp = nullTimestamp != null ? new Timestamp(nullTimestamp.getTime()) : null;
}
/**
* Sets the value to return when a SQL null is encountered as the result of
* invoking a getURL method.
*
* @param nullURL the value
*/
public void setNullURL(URL nullURL) {
this.nullURL = nullURL;
}
}