mozilla
/
gecko-dev
зеркало из https://github.com/mozilla/gecko-dev.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность

Examples now uses try {} finally { Context.exit(); } to release Context even in case of errors

This commit is contained in:
igor%mir2.org 2002-07-09 17:49:16 +00:00
Родитель 2f03420b5d
Коммит 1cf0bd8a05
6 изменённых файлов: 198 добавлений и 156 удалений
Показать статистику Скачать Patch файл Скачать Diff файл Показать все файлы Свернуть все файлы

109
js/rhino/docs/tutorial.html
Просмотреть файл

@ -139,10 +139,14 @@ that we use in later calls.
<p><a NAME="Collecting"></a><font size=+2>Collecting the arguments</font>
<p>This code is standard Java and not specific to Rhino. It just collects
all the arguments and concatenates them together.
<blockquote><tt><font color="#006600">String s = "";</font></tt>
<br><tt><font color="#006600">for (int i=0; i &lt; args.length; i++)</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; s += args[i];</font></tt></blockquote>
<blockquote>
<pre style="color: #006600">
String s = "";
for (int i=0; i &lt; args.length; i++) {
s += args[i];
}
</pre>
</blockquote>
<p><br><a NAME="Evaluating"></a><font size=+2>Evaluating a script</font>
<p>The code
<blockquote>
@ -166,11 +170,15 @@ method converts any JavaScript value to a string.
<p><a NAME="Exit"></a><font size=+2>Exit the Context</font>
<p>The code
<blockquote>
<pre><font color="#006600">Context.exit();</font></pre>
<pre style="color: #006600">
} finally {
Context.exit();
}
</pre>
</blockquote>
exits the Context. This removes the association between the Context and
the current thread and is an essential cleanup action. There should be
a call to <tt>exit</tt> for every call to <tt>enter</tt>.
a call to <tt>exit</tt> for every call to <tt>enter</tt>. To make sure that it is called even if an exception is thrown, it is put into the finally block corresponding to the try block starting after <tt>Context.enter()</tt>.
<br>&nbsp;
<dir>&nbsp;</dir>
<a NAME="Expose"></a><font size=+3>Expose Java APIs</font>
@ -219,40 +227,45 @@ is illustrated in the <a href="http://lxr.mozilla.org/mozilla/source/js/rhino/ex
example. This example adds the ability to print the value of variable <tt>x</tt>
and the result of calling function <tt>f</tt>. Both <tt>x</tt> and <tt>f</tt>
are expected to be defined by the evaluated script. For example,
<blockquote><tt><font color="#663366">$ java RunScript3 'x = 7'</font></tt>
<br><tt><font color="#663366">x = 7</font></tt>
<br><tt><font color="#663366">f is undefined or not a function.</font></tt>
<br><tt><font color="#663366">$ java RunScript3 'function f(a) { return
a; }'</font></tt>
<br><tt><font color="#663366">x is not defined.</font></tt>
<br><tt><font color="#663366">f('my args') = my arg</font></tt>
<br><tt><font color="#663366"></font></tt>&nbsp;</blockquote>
<blockquote>
<pre style="color: #663366">
$ java RunScript3 'x = 7'
x = 7
f is undefined or not a function.
$ java RunScript3 'function f(a) { return a; }'
x is not defined.
f('my args') = my arg
</pre>
</blockquote>
<a NAME="UsingJSvars"></a><font size=+2>Using JavaScript variables</font>
<p>To print out the value of <tt>x</tt>, we add the following code.
<dir><tt><font color="#006600">Object x = scope.get("x", scope);</font></tt>
<br><tt><font color="#006600">if (x == Scriptable.NOT_FOUND)</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; System.out.println("x
is not defined.");</font></tt>
<br><tt><font color="#006600">else</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; System.out.println("x
= " + Context.toString(x));</font></tt>
<br><tt><font color="#006600"></font></tt>&nbsp;</dir>
<blockquote>
<pre style="color: #006600">
Object x = scope.get("x", scope);
if (x == Scriptable.NOT_FOUND) {
System.out.println("x is not defined.");
} else {
System.out.println("x = " + Context.toString(x));
}
</pre>
</blockquote>
<a NAME="CallingJSfuns"></a><font size=+2>Calling JavaScript functions</font>
<p>To get the function <tt>f</tt>, call it, and print the result, we add
this code:
<dir><tt><font color="#006600">Object f = scope.get("f", scope);</font></tt>
<br><tt><font color="#006600">if (!(f instanceof Function))</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; System.out.println("f
is undefined or not a function.");</font></tt>
<br><tt><font color="#006600">else {</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; Object functionArgs[]
= { "my arg" };</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; Object result = ((Function)
f).call(cx, scope, scope, functionArgs);</font></tt>
<br><tt><font color="#006600">&nbsp;&nbsp;&nbsp; System.out.println("f('my
args') = " + Context.toString(result));</font></tt>
<br><tt><font color="#006600">}</font></tt></dir>
<blockquote>
<pre style="color: #006600">
Object fObj = scope.get("f", scope);
if (!(fObj instanceof Function)) {
System.out.println("f is undefined or not a function.");
} else {
Object functionArgs[] = { "my arg" };
Function f = (Function)fObj;
Object result = f.call(cx, scope, scope, functionArgs);
String report = "f('my args') = " + Context.toString(result);
System.out.println(report);
}
</pre>
</blockquote>
<p><br><a NAME="JavaScriptHostObjects"></a><font size=+3>JavaScript host
objects</font>
<p><a NAME="DefiningHostObjects"></a><font size=+2>Defining Host Objects</font>
@ -267,7 +280,8 @@ built-in <tt>defineClass</tt> function. We'll see how to add it to RunScript
later. (Note that because the <tt>java -jar</tt> option preempts the rest
of the classpath, we can't use that and access the <tt>Counter</tt> class.)
<blockquote>
<pre><font color="#663366">$ java -cp 'js.jar;examples' org.mozilla.javascript.tools.shell.Main
<pre style="color: #663366">
$ java -cp 'js.jar;examples' org.mozilla.javascript.tools.shell.Main
js> defineClass("Counter")
js> c = new Counter(7)
[object Counter]
@ -279,7 +293,8 @@ js> c.count
9
js> c.resetCount()
js> c.count
0</font></pre>
0
</pre>
</blockquote>
<a NAME="CounterCtors"></a><font size=+2>Counter's constructors</font>
<p>The zero-argument constructor is used by Rhino runtime to create instances.
@ -323,14 +338,20 @@ c.count;'</font></tt>
It also creates a new instance of the <tt>Counter</tt> object from within
our Java code, constructing it with the value 7, and assigning it to the
top-level variable <tt>myCounter</tt>:
<dir><tt><font color="#006600">Object[] arg = { new Integer(7) };</font></tt>
<br><tt><font color="#006600">Scriptable myCounter = cx.newObject(scope,
"Counter", arg);</font></tt>
<br><tt><font color="#006600">scope.put("myCounter", scope, myCounter);</font></tt></dir>
<blockquote>
<pre style="color: #006600">
Object[] arg = { new Integer(7) };
Scriptable myCounter = cx.newObject(scope, "Counter", arg);
scope.put("myCounter", scope, myCounter);
</pre>
</blockquote>
Now we can reference the <tt>myCounter</tt> object from our script:
<dir><tt><font color="#663366">$ java RunScript3 'RunScript4 'myCounter.count;
myCounter.count'</font></tt>
<br><tt><font color="#663366">8</font></tt></dir>
<blockquote>
<pre style="color: #663366">
$ java RunScript3 'RunScript4 'myCounter.count; myCounter.count'
8
</pre>
</blockquote>
</body>
</html>

40
js/rhino/examples/CounterTest.java
Просмотреть файл

@ -18,7 +18,7 @@
* Copyright (C) 1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Contributor(s):
* Norris Boyd
*
* Alternatively, the contents of this file may be used under the
@ -49,27 +49,31 @@ import org.mozilla.javascript.*;
*/
public class CounterTest {
public static void main(String[] args) throws Exception
{
Context cx = Context.enter();
Scriptable scope = cx.initStandardObjects(null);
ScriptableObject.defineClass(scope, Counter.class);
public static void main(String[] args) throws Exception
{
Context cx = Context.enter();
try {
Scriptable scope = cx.initStandardObjects(null);
ScriptableObject.defineClass(scope, Counter.class);
Scriptable testCounter = cx.newObject(scope, "Counter");
Object count = ScriptableObject.getProperty(testCounter, "count");
System.out.println("count = " + count);
Scriptable testCounter = cx.newObject(scope, "Counter");
count = ScriptableObject.getProperty(testCounter, "count");
System.out.println("count = " + count);
Object count = ScriptableObject.getProperty(testCounter, "count");
System.out.println("count = " + count);
ScriptableObject.callMethod(testCounter, "resetCount", new Object[0]);
System.out.println("resetCount");
count = ScriptableObject.getProperty(testCounter, "count");
System.out.println("count = " + count);
count = ScriptableObject.getProperty(testCounter, "count");
System.out.println("count = " + count);
ScriptableObject.callMethod(testCounter,
"resetCount",
new Object[0]);
System.out.println("resetCount");
Context.exit();
}
count = ScriptableObject.getProperty(testCounter, "count");
System.out.println("count = " + count);
} finally {
Context.exit();
}
}
}

53
js/rhino/examples/RunScript.java
Просмотреть файл

@ -18,7 +18,7 @@
* Copyright (C) 1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License (the "GPL"), in which case the
@ -36,38 +36,41 @@ import org.mozilla.javascript.*;
/**
* RunScript: simplest example of controlling execution of Rhino.
*
* Collects its arguments from the command line, executes the
*
* Collects its arguments from the command line, executes the
* script, and prints the result.
*
*
* @author Norris Boyd
*/
public class RunScript {
public static void main(String args[])
throws JavaScriptException
public static void main(String args[])
throws JavaScriptException
{
// Creates and enters a Context. The Context stores information
// about the execution environment of a script.
Context cx = Context.enter();
// Initialize the standard objects (Object, Function, etc.)
// This must be done before scripts can be executed. Returns
// a scope object that we use in later calls.
Scriptable scope = cx.initStandardObjects(null);
// Collect the arguments into a single string.
String s = "";
for (int i=0; i < args.length; i++)
s += args[i];
// Now evaluate the string we've colected.
Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
// Convert the result to a string and print it.
System.err.println(cx.toString(result));
// Exit from the context.
Context.exit();
try {
// Initialize the standard objects (Object, Function, etc.)
// This must be done before scripts can be executed. Returns
// a scope object that we use in later calls.
Scriptable scope = cx.initStandardObjects(null);
// Collect the arguments into a single string.
String s = "";
for (int i=0; i < args.length; i++) {
s += args[i];
}
// Now evaluate the string we've colected.
Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
// Convert the result to a string and print it.
System.err.println(cx.toString(result));
} finally {
// Exit from the context.
Context.exit();
}
}
}

36
js/rhino/examples/RunScript2.java
Просмотреть файл

@ -18,7 +18,7 @@
* Copyright (C) 1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License (the "GPL"), in which case the
@ -36,27 +36,31 @@ import org.mozilla.javascript.*;
/**
* RunScript2: Like RunScript, but reflects the System.out into JavaScript.
*
*
* @author Norris Boyd
*/
public class RunScript2 {
public static void main(String args[])
throws JavaScriptException
public static void main(String args[])
throws JavaScriptException
{
Context cx = Context.enter();
Scriptable scope = cx.initStandardObjects(null);
try {
Scriptable scope = cx.initStandardObjects(null);
// Add a global variable "out" that is a JavaScript reflection
// of System.out
Scriptable jsArgs = Context.toObject(System.out, scope);
scope.put("out", scope, jsArgs);
String s = "";
for (int i=0; i < args.length; i++)
s += args[i];
Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
System.err.println(cx.toString(result));
Context.exit();
// Add a global variable "out" that is a JavaScript reflection
// of System.out
Scriptable jsArgs = Context.toObject(System.out, scope);
scope.put("out", scope, jsArgs);
String s = "";
for (int i=0; i < args.length; i++) {
s += args[i];
}
Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
System.err.println(cx.toString(result));
} finally {
Context.exit();
}
}
}

68
js/rhino/examples/RunScript3.java
Просмотреть файл

@ -18,7 +18,7 @@
* Copyright (C) 1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License (the "GPL"), in which case the
@ -36,45 +36,51 @@ import org.mozilla.javascript.*;
/**
* RunScript3: Example of using JavaScript objects
*
* Collects its arguments from the command line, executes the
*
* Collects its arguments from the command line, executes the
* script, and then ...
*
*
* @author Norris Boyd
*/
public class RunScript3 {
public static void main(String args[])
throws JavaScriptException
public static void main(String args[])
throws JavaScriptException
{
Context cx = Context.enter();
Scriptable scope = cx.initStandardObjects(null);
// Collect the arguments into a single string.
String s = "";
for (int i=0; i < args.length; i++)
s += args[i];
// Now evaluate the string we've colected. We'll ignore the result.
cx.evaluateString(scope, s, "<cmd>", 1, null);
try {
Scriptable scope = cx.initStandardObjects(null);
// Print the value of variable "x"
Object x = scope.get("x", scope);
if (x == Scriptable.NOT_FOUND)
System.out.println("x is not defined.");
else
System.out.println("x = " + Context.toString(x));
// Collect the arguments into a single string.
String s = "";
for (int i=0; i < args.length; i++) {
s += args[i];
}
// Call function "f('my arg')" and print its result.
Object f = scope.get("f", scope);
if (!(f instanceof Function))
System.out.println("f is undefined or not a function.");
else {
Object functionArgs[] = { "my arg" };
Object result = ((Function) f).call(cx, scope, scope, functionArgs);
System.out.println("f('my args') = " + Context.toString(result));
// Now evaluate the string we've colected. We'll ignore the result.
cx.evaluateString(scope, s, "<cmd>", 1, null);
// Print the value of variable "x"
Object x = scope.get("x", scope);
if (x == Scriptable.NOT_FOUND) {
System.out.println("x is not defined.");
} else {
System.out.println("x = " + Context.toString(x));
}
// Call function "f('my arg')" and print its result.
Object fObj = scope.get("f", scope);
if (!(fObj instanceof Function)) {
System.out.println("f is undefined or not a function.");
} else {
Object functionArgs[] = { "my arg" };
Function f = (Function)fObj;
Object result = f.call(cx, scope, scope, functionArgs);
String report = "f('my args') = " + Context.toString(result);
System.out.println(report);
}
} finally {
Context.exit();
}
Context.exit();
}
}

48
js/rhino/examples/RunScript4.java
Просмотреть файл

@ -18,7 +18,7 @@
* Copyright (C) 1999 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License (the "GPL"), in which case the
@ -37,34 +37,38 @@ import org.mozilla.javascript.*;
/**
* RunScript4: Execute scripts in an environment that includes the
* example Counter class.
*
*
* @author Norris Boyd
*/
public class RunScript4 {
public static void main(String args[])
throws Exception
public static void main(String args[])
throws Exception
{
Context cx = Context.enter();
Scriptable scope = cx.initStandardObjects(null);
try {
Scriptable scope = cx.initStandardObjects(null);
// Use the Counter class to define a Counter constructor
// and prototype in JavaScript.
ScriptableObject.defineClass(scope, Counter.class);
// Use the Counter class to define a Counter constructor
// and prototype in JavaScript.
ScriptableObject.defineClass(scope, Counter.class);
// Create an instance of Counter and assign it to
// the top-level variable "myCounter". This is
// equivalent to the JavaScript code
// myCounter = new Counter(7);
Object[] arg = { new Integer(7) };
Scriptable myCounter = cx.newObject(scope, "Counter", arg);
scope.put("myCounter", scope, myCounter);
String s = "";
for (int i=0; i < args.length; i++)
s += args[i];
Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
System.err.println(cx.toString(result));
Context.exit();
// Create an instance of Counter and assign it to
// the top-level variable "myCounter". This is
// equivalent to the JavaScript code
// myCounter = new Counter(7);
Object[] arg = { new Integer(7) };
Scriptable myCounter = cx.newObject(scope, "Counter", arg);
scope.put("myCounter", scope, myCounter);
String s = "";
for (int i=0; i < args.length; i++) {
s += args[i];
}
Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
System.err.println(cx.toString(result));
} finally {
Context.exit();
}
}
}