client.java

Java的面向对象数据库系统的源代码

import org.ozoneDB.ExternalDatabase;

/**
 * $Id: Client.java,v 1.3.2.1 2003/12/21 16:01:22 per_nyfelt Exp $
 */
public class Client {

    private Foo foo;
    private Bar bar;
    private Delegate delegate;

    public static void main(String[] args) throws Exception {
       String url= "ozonedb:remote://localhost:3333";
        if (args.length > 0) {
            url = args[0];
        }
        Client client = new Client();
        client.runSample(url);

    }

    public void runSample(String url) throws Exception {

        ExternalDatabase db = ExternalDatabase.openDatabase(url);

        foo = (Foo)db.objectForName("foo");
        if (foo == null) {
            foo = (Foo)db.createObject(FooImpl.class);
        }

        bar = (Bar)db.objectForName("bar");
        if (bar == null) {
            bar = (Bar)db.createObject(BarImpl.class);
        }

        delegate = (Delegate) db.objectForName("delegate");
        if (delegate == null) {
            delegate = (Delegate)db.createObject(
                            DelegateImpl.class,
                            new Class[] {Foo.class, Bar.class},
                            new Object[] {foo, bar}
                        );
        }

        // fisrt a simple test, we expect no issues here
        foo.setA("hej");
        foo.setB("bla");
        bar.setC(56);

        if (checkValues("hej", "bla", 56)) {
            System.out.println("OK, Simple test, All values set correctly");
        } else {
            System.out.println("Error, Failed to set simple values");
        }
        printValues();


        // now lets try to use the delegate for a build update of foo and bar
        // again no issues are expected
        delegate.updateFooBar("qwe", "rty", 123);
        if (checkValues("qwe", "rty", 123)) {
            System.out.println("OK, Bulk update test, All values set correctly");
        } else {
            System.out.println("Error, Failed to set values using delegate");
        }
        printValues();

        // now lets try use values that will cause an exception and roll back
        try {
            delegate.updateFooBar("asd", "dfg", 23);
        } catch (Exception e) {
            System.out.println("OK, updateFooBarFailed");
        }
        // this would be bad, the roll back failed
        if (checkValues("asd", "dfg", 23)) {
            System.out.println("Error, Failed to roll back properly!!!");
        // the expected outcome
        } else if (checkValues("qwe", "rty", 123)){
            System.out.println("OK, Bulk update test, All values rolled back correctly");
        // something else wierd has happened
        } else {
           System.out.println("Error, Failed to roll back properly");
        }
        printValues();

        // do it again on updateFooBar2 which does not execute as a transactional unit
        delegate.updateFooBar2("asd", "dfg", 23);

        if (checkValues("asd", "dfg", 123)) {
            System.out.println("OK, only partial roll back (as expected)");
        } else if (checkValues("qwe", "rty", 123)){
            System.out.println("Error, Bulk update test2, All values rolled back");
        } else {
           System.out.println("Error, unexpected result");
        }
        printValues();

        db.close();
    }

    private void printValues() {
        System.out.println("\t aVal = " + foo.getA() + ", bVal = " + foo.getB() + ", cVal = " + bar.getC());
    }

    private boolean checkValues(String aVal, String bVal, int cVal) {
        if (aVal.equals((foo.getA())) && (bVal.equals(foo.getB())) && (cVal == bar.getC())) {
            return true;
        } else {
            return false;
        }
    }
}