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The Java Developers Almanac 1.4 |
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e6. Getting and Setting a Property of a BeanThis example demonstrates how to get and set the value of a property in a bean usingExpression and Statement. The example gets
and sets three types of properties, an Object, a primitive type,
and an array. Both these classes use the name of the method that gets
or sets the property.
Object o = new MyBean();
try {
// Get the value of prop1
Expression expr = new Expression(o, "getProp1", new Object[0]);
expr.execute();
String s = (String)expr.getValue();
// Set the value of prop1
Statement stmt = new Statement(o, "setProp1", new Object[]{"new string"});
stmt.execute();
// Get the value of prop2
expr = new Expression(o, "getProp2", new Object[0]);
expr.execute();
int i = ((Integer)expr.getValue()).intValue();
// Set the value of prop2
stmt = new Statement(o, "setProp2", new Object[]{new Integer(123)});
stmt.execute();
// Get the value of prop1
expr = new Expression(o, "getProp3", new Object[0]);
expr.execute();
byte[] bytes = (byte[])expr.getValue();
// Set the value of prop1
stmt = new Statement(o, "setProp3", new Object[]{new byte[]{0x12, 0x23}});
stmt.execute();
} catch (Exception e) {
}
public class MyBean {
// Property prop1
String prop1;
public String getProp1() {
return prop1;
}
public void setProp1(String s) {
prop1 = s;
}
// Property prop2
int prop2;
public int getProp2() {
return prop2;
}
public void setProp2(int i) {
prop2 = i;
}
// Property prop3
byte[] prop3;
public byte[] getProp3() {
return prop3;
}
public void setProp3(byte[] bytes) {
prop3 = bytes;
}
}
e2. Implementing a Bound Property e3. Implementing a Constrained Property e4. Instantiating a Bean e5. Listing the Property Names of a Bean
© 2002 Addison-Wesley. |