Archive for the ‘Development’ Category
Java to XML, XML to Java (Marshalling and Unmarshalling)
Wednesday, July 13th, 2011
Introduction
JDK6 and JAXB2.x (which comes with JDK6) make marshalling Java to XML and unmarshalling XML to Java a snap, almost trivial.
Example
Java to XML
package foo.bar;
import java.math.BigDecimal;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
public class JavaToXML {
public static void main(String[] args) throws Exception {
JAXBContext context = JAXBContext.newInstance(Product.class);
Marshaller m = context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
Product object = new Product();
object.setCode("WI1");
object.setName("Widget Number One");
object.setPrice(BigDecimal.valueOf(300.00));
m.marshal(object, System.out);
}
}
XML to Java
package foo.bar;
import java.io.File;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
public class XMLToJava {
public static void main(String[] args) {
try {
JAXBContext jc = JAXBContext.newInstance(Product.class);
Unmarshaller u = jc.createUnmarshaller();
File f = new File("product.xml");
Product product = (Product) u.unmarshal(f);
System.out.println(product.getCode());
System.out.println(product.getName());
System.out.println(product.getPrice());
} catch (JAXBException e) {
e.printStackTrace();
}
}
}
product.java
Note: the @XmlRootElement is vital here!
package foo.bar;
import java.math.BigDecimal;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class Product {
private String code;
private String name;
private BigDecimal price;
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public BigDecimal getPrice() {
return price;
}
public void setPrice(BigDecimal price) {
this.price = price;
}
}
product.xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<product>
<code>WI1</code>
<name>Widget Number One</name>
<price>300.0</price>
</product>
Tags: java, jaxb, xml
Posted in Examples | 8 Comments »
The Processing Instruction Target Matching “[xX][mM][lL]” is Not Allowed
Friday, June 24th, 2011
Background
When parsing XML you receive the following error:
...The Processing Instruction Target Matching "[xX][mM][lL]" is Not Allowed...
Solution
The chances are you have some sort of whitespace (or control character) infront of your XML declaration:
..<?xml version="1.0" encoding="utf-8"?>
It may even be that you have more than one XML declaration in the document..!
Tags: xml
Posted in quick tips | No Comments »
Read a File as String with Java
Thursday, June 16th, 2011
Introduction
I’m always Googling for a way to do this. This seems to be the best “idiomatic” solution I’ve found. So without further ado…
Example
public String readFile(String path) throws IOException {
FileInputStream stream = new FileInputStream(new File(path));
try{
FileChannel fc = stream.getChannel();
MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
return Charset.defaultCharset().decode(bb).toString();
}
finally {
stream.close();
}
}
Tags: java
Posted in Development, How to's, quick tips | No Comments »
View Source of Oracle Trigger
Wednesday, May 11th, 2011
select trigger_body from user_triggers where trigger_name = 'XXXXX'
Tags: oracle, sql
Posted in quick tips | No Comments »
Unit Test Private Java Methods using Reflection
Thursday, May 5th, 2011
Introduction
I realise that the thought of Unit Testing private methods in Java classes can be like a red rag to a bull for some people and I understand the arguments.
Therefore, I present the following as a “how to”, not a moral argument for or against!
Example
The class under test
public class Product() {
private String privateMethod(String id) {
//Do something private
return "product_" + id;
}
}
The (Reflection Based) Unit Test
import java.lang.reflect.Method;
import static org.junit.Assert.*;
import org.junit.Test;
public class ProductTest {
private Product product; // the class under test
private Method m;
private static String METHOD_NAME = "privateMethod";
private Class[] parameterTypes;
private Object[] parameters;
@Before
public void setUp() throws Exception {
product = new Product();
parameterTypes = new Class[1];
parameterTypes[0] = java.lang.String.class;
m = product.getClass().getDeclaredMethod(METHOD_NAME, parameterTypes);
m.setAccessible(true);
parameters = new Object[1];
}
@Test
public void testPrivateMethod() throws Exception {
parameters[0] = "someIdentifier";
String result = (String) m.invoke(product, parameters);
//Do your assertions
assertNotNull(result);
}
}
Update
I’ve since been told that if dp4j.jar is in the classpath at compile-time, it will inject the necessary reflection to make this work. I haven’t had time to try this yet so YMMV.
Tags: java, junit, testing
Posted in Development, How to's | No Comments »