diff options
Diffstat (limited to 'tutorial')
| -rw-r--r-- | tutorial/tutorial.html | 58 |
1 files changed, 33 insertions, 25 deletions
diff --git a/tutorial/tutorial.html b/tutorial/tutorial.html index 097d695a..b6876d4c 100644 --- a/tutorial/tutorial.html +++ b/tutorial/tutorial.html @@ -140,19 +140,37 @@ not permitted. This is for warning the developers when they attempt to modify a class file that has been already loaded since the JVM does not allow reloading a class. -<p>When Javassist freezes a <code>CtClass</code> object, it also -prunes the data structure contained in that object. To reduce memory -consumption, Javassist discards unnecessary attributes +<p>A frozen <code>CtClass</code> can be defrost so that +modifications of the class definition will be permitted. For example, + +<ul><pre> +CtClasss cc = ...; + : +cc.writeFile(); +cc.defrost(); +cc.setSuperclass(...); // OK since the class is not frozen. +</pre></ul> + +<p>After <code>defrost()</code> is called, the <code>CtClass</code> +object can be modified again. + +<p>If <code>ClassPool.doPruning</code> is set to <code>true</code>, +then Javassist prunes the data structure contained +in a <code>CtClass</code> object +when Javassist freezes that object. +To reduce memory +consumption, pruning discards unnecessary attributes (<code>attribute_info</code> structures) in that object. For example, <code>Code_attribute</code> structures (method bodies) are discarded. Thus, after a <code>CtClass</code> object is pruned, the bytecode of a method is not -accessible although method names, signatures, and annotations -are still accessible. +accessible except method names, signatures, and annotations. +The pruned <code>CtClass</code> object cannot be defrost again. +The default value of <code>ClassPool.doPruning</code> is <code>false</code>. -<p>To disallow pruning a <code>CtClass</code>, <code>stopPruning()</code> -must be called in advance: +<p>To disallow pruning a particular <code>CtClass</code>, +<code>stopPruning()</code> must be called on that object in advance: <ul><pre> CtClasss cc = ...; @@ -162,29 +180,19 @@ cc.writeFile(); // convert to a class file. // cc is not pruned. </pre></ul> -<p>If a <code>CtClass</code> is not pruned, it can be defrost so that -modifications of the class definition can be permitted. For example, - -<ul><pre> -CtClasss cc = ...; -cc.stopPruning(true); - : -cc.writeFile(); -cc.defrost(); -cc.setSuperclass(...); // OK since the class is not frozen. -</pre></ul> - -<p>To disallow pruning for all the <code>CtClass</code>es, set -<code>ClassPool.doPruning</code> to <code>false</code>. +<p>The <code>CtClass</code> object <code>cc</code> is not pruned. +Thus it can be defrost after <code>writeFile()</code> is called. <ul><b>Note:</b> -While debugging, you might want to temporarily stop pruning and write a modified -class file to a disk drive. <code>debugWriteFile()</code> is a convenient method -for that purpose. It stops pruning, write a class file, defrost it, and turn -pruning on again (if it was initially on). +While debugging, you might want to temporarily stop pruning and freezing +and write a modified class file to a disk drive. +<code>debugWriteFile()</code> is a convenient method +for that purpose. It stops pruning, writes a class file, defrosts it, +and turns pruning on again (if it was initially on). </ul> + <h4>Class search path</h4> <p>The default <code>ClassPool</code> returned |