public class OutputDirectiveFactory
extends Object
OutputDirectiveFactory
用于定制自定义输出指令，替换系统默认输出指令，满足个性化需求
用法：
1：定义 MyOutput
public class MyOutput extends Output {
public MyOutput(ExprList exprList) {
super(exprList);
}
public void exec(Env env, Scope scope, Writer writer) {
Object value = exprList.eval(scope);
if (value != null) {
write(writer, value.toString());
}
}
}
2：定义 MyOutputDirectiveFactory
public class MyOutputDirectiveFactory extends OutputDirectiveFactory {
public Output getOutputDirective(ExprList exprList) {
return new MyOutput(exprList);
}
}
3：配置
engine.setOutputDirectiveFactory(new MyOutputDirectiveFactory())