org.jboss.byteman.contrib.dtest.RuleBuilder Maven / Gradle / Ivy

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/*
 * JBoss, Home of Professional Open Source
 * Copyright 2010, Red Hat, Inc. and/or its affiliates,
 * and individual contributors as indicated by the @author tags.
 * See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU Lesser General Public License, v. 2.1.
 * This program is distributed in the hope that it will be useful, but WITHOUT A
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
 * You should have received a copy of the GNU Lesser General Public License,
 * v.2.1 along with this distribution; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 *
 * (C) 2010,
 * @author JBoss, by Red Hat.
 */
package org.jboss.byteman.contrib.dtest;

/**
 * Provides a fluent API for creating Byteman rules without needing
 *  to mess around with String concatenation.
 *
 * Example:
 *
 * RuleBuilder rb = new RuleBuilder("myRule");
 * rb.onClass("org.jboss.byteman.ExampleClass")
 *   .inMethod("doInterestingStuff")
 *   .whenTrue().doAction("myAction()");
 *  System.out.println(rb);
 *
 * will print:
 *
 *   RULE myRule
 *   CLASS org.jboss.byteman.ExampleClass
 *   METHOD doInterestingStuff
 *   AT ENTRY
 *   IF true
 *   DO myAction()
 *   ENDRULE
 *
 * @deprecated use {@link RuleConstructor}
 * @author Jonathan Halliday ([email protected]) 2010-05
 */
@Deprecated
public class RuleBuilder
{
    public static void main(String[] args) {
        RuleBuilder rb = new RuleBuilder("myRule");
        rb.onClass("org.jboss.byteman.ExampleClass")
          .inMethod("doInterestingStuff")
          .atEntry()
          .whenTrue()
          .doAction("myAction()");
        System.out.println(rb);
    }

    private String ruleName;
    private String className;
    private boolean isInterface;
    private String methodName;
    private String helperName;
    private String atClause = "ENTRY";
    private String ifClause = "true";
    private String doClause;

    public RuleBuilder(String ruleName) {
        this.ruleName = ruleName;
    }

    public RuleBuilder onClass(Class clazz) {
        return onSpecifier(clazz.getCanonicalName(), false);
    }

    public RuleBuilder onClass(String className) {
        return onSpecifier(className, false);
    }

    public RuleBuilder onInterface(Class clazz) {
        return onSpecifier(clazz.getCanonicalName(), true);
    }

    public RuleBuilder onInterface(String className) {
        return onSpecifier(className, true);
    }

    private RuleBuilder onSpecifier(String className, boolean isInterface) {
        this.className = className;
        this.isInterface = isInterface;
        return this;
    }

    public RuleBuilder inMethod(String methodName) {
        this.methodName = methodName;
        return this;
    }

    public RuleBuilder usingHelper(Class helperClass) {
        return usingHelper(helperClass.getCanonicalName());
    }

    public RuleBuilder usingHelper(String helperName) {
        this.helperName = helperName;
        return this;
    }

    public RuleBuilder at(String at) {
        atClause = at;
        return this;
    }

    public RuleBuilder atEntry() {
        return at("ENTRY");
    }

    public RuleBuilder atExit() {
        return at("EXIT");
    }

    public RuleBuilder atLine(int line) {
        return at("LINE "+line);
    }

    public RuleBuilder when(String condition) {
        ifClause = condition;
        return this;
    }

    public RuleBuilder whenTrue() {
        return when("true");
    }

    public RuleBuilder whenFalse() {
        return when("false");
    }

    public RuleBuilder when(boolean when) {
        return when(""+when);
    }

    public RuleBuilder doAction(String action) {
        doClause = action;
        return this;
    }

    private static String LINEBREAK = "\n";

    @Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder();

        stringBuilder.append("RULE ");
        stringBuilder.append(ruleName);
        stringBuilder.append(LINEBREAK);

        if(isInterface) {
            stringBuilder.append("INTERFACE ");
        } else {
            stringBuilder.append("CLASS ");
        }
        stringBuilder.append(className);
        stringBuilder.append(LINEBREAK);

        stringBuilder.append("METHOD ");
        stringBuilder.append(methodName);
        stringBuilder.append(LINEBREAK);

        if(helperName != null) {
            stringBuilder.append("HELPER ");
            stringBuilder.append(helperName);
            stringBuilder.append(LINEBREAK);
        }

        stringBuilder.append("AT ");
        stringBuilder.append(atClause);
        stringBuilder.append(LINEBREAK);

        // bind

        stringBuilder.append("IF ");
        stringBuilder.append(ifClause);
        stringBuilder.append(LINEBREAK);

        stringBuilder.append("DO ");
        stringBuilder.append(doClause);
        stringBuilder.append(LINEBREAK);

        stringBuilder.append("ENDRULE");
        stringBuilder.append(LINEBREAK);

        return stringBuilder.toString();
    }
}