public class SecureClassLoader
extends ClassLoader
| java.lang.Object | ||
| ↳ | java.lang.ClassLoader | |
| ↳ | java.security.SecureClassLoader | |
 Known Direct Subclasses
|
该类扩展了ClassLoader，额外支持定义具有相关代码源和权限的类，这些代码源和权限默认由系统策略检索。
Protected constructors |
|
|---|---|
SecureClassLoader(ClassLoader parent) 使用指定的父类加载器为委派创建新的SecureClassLoader。 |
|
SecureClassLoader() 使用用于委派的默认父类加载器创建新的SecureClassLoader。 |
|
Protected methods |
|
|---|---|
final Class<?> |
defineClass(String name, byte[] b, int off, int len, CodeSource cs) 使用可选的CodeSource将字节数组转换为类Class的实例。 |
final Class<?> |
defineClass(String name, ByteBuffer b, CodeSource cs) 使用可选的CodeSource将 |
PermissionCollection |
getPermissions(CodeSource codesource) 返回给定CodeSource对象的权限。 |
Inherited methods |
|
|---|---|
From class java.lang.ClassLoader
|
|
From class java.lang.Object
|
|
SecureClassLoader (ClassLoader parent)
使用指定的父类加载器为委派创建新的SecureClassLoader。
如果存在安全管理器，则此方法首先调用安全管理器的方法 checkCreateClassLoader以确保允许创建类加载器。
| Parameters | |
|---|---|
parent |
ClassLoader: the parent ClassLoader |
| Throws | |
|---|---|
SecurityException |
if a security manager exists and its checkCreateClassLoader method doesn't allow creation of a class loader. |
也可以看看：
SecureClassLoader ()
使用用于委派的默认父类加载器创建新的SecureClassLoader。
如果有安全管理器，则此方法首先调用安全管理器的 checkCreateClassLoader方法以确保允许创建类加载器。
| Throws | |
|---|---|
SecurityException |
if a security manager exists and its checkCreateClassLoader method doesn't allow creation of a class loader. |
也可以看看：
Class<?> defineClass (String name, byte[] b, int off, int len, CodeSource cs)
使用可选的CodeSource将字节数组转换为类Class的实例。 在课程可以使用之前，必须解决。
如果提供了非空的CodeSource，则构造一个ProtectionDomain并将其与正在定义的类关联。
| Parameters | |
|---|---|
name |
String: the expected name of the class, or null if not known, using '.' and not '/' as the separator and without a trailing ".class" suffix. |
b |
byte: the bytes that make up the class data. The bytes in positions off through off+len-1 should have the format of a valid class file as defined by The Java™ Virtual Machine Specification. |
off |
int: the start offset in b of the class data |
len |
int: the length of the class data |
cs |
CodeSource: the associated CodeSource, or null if none |
| Returns | |
|---|---|
Class<?> |
the Class object created from the data, and optional CodeSource. |
| Throws | |
|---|---|
ClassFormatError |
if the data did not contain a valid class |
IndexOutOfBoundsException |
if either off or len is negative, or if off+len is greater than b.length. |
SecurityException |
if an attempt is made to add this class to a package that contains classes that were signed by a different set of certificates than this class, or if the class name begins with "java.". |
Class<?> defineClass (String name, ByteBuffer b, CodeSource cs)
使用可选的CodeSource将ByteBuffer转换为类Class的实例。 在课程可以使用之前，必须解决。
如果提供了非空的CodeSource，则构造一个ProtectionDomain并将其与正在定义的类关联。
| Parameters | |
|---|---|
name |
String: the expected name of the class, or null if not known, using '.' and not '/' as the separator and without a trailing ".class" suffix. |
b |
ByteBuffer: the bytes that make up the class data. The bytes from positions b.position() through b.position() + b.limit() -1 should have the format of a valid class file as defined by The Java™ Virtual Machine Specification. |
cs |
CodeSource: the associated CodeSource, or null if none |
| Returns | |
|---|---|
Class<?> |
the Class object created from the data, and optional CodeSource. |
| Throws | |
|---|---|
ClassFormatError |
if the data did not contain a valid class |
SecurityException |
if an attempt is made to add this class to a package that contains classes that were signed by a different set of certificates than this class, or if the class name begins with "java.". |
PermissionCollection getPermissions (CodeSource codesource)
返回给定CodeSource对象的权限。
此方法由defineClass方法调用，该方法在为正在定义的类构造ProtectionDomain时将CodeSource作为参数。
| Parameters | |
|---|---|
codesource |
CodeSource: the codesource. |
| Returns | |
|---|---|
PermissionCollection |
the permissions granted to the codesource. |
Android开发手册