实例分析JVM安全体系：双亲委派、命名空间、保护域、策略-Java开发Java经验技巧

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18、;import java.io.inputstream;publie class myclassloader extends classloader ? private string name; ? /oooau3? private string path = ne:workspaceclassloadertesth;?/oo0a-? private static final string home =ne : workspace wclassloadertestw11;? private final string classfiletype = 11. class11;? public my

19、classloader(string name) ? super ();? = name;? ? public myclassloader(classloader parent, string name) ? super(parent);? = name;? ? 0override? public string tostring ()? return ;? ? public string getpath()? return path;? ? public void setpath (string path) ? this pdth =

20、path;? ? override? public class<?> findclass (string name) throws classnotfoundexception? byte data = this.loadclassdata(name);? if (data = null)? throw new classnotfoundexception();? return this.defineclass(name, data, 0, datalength);? ? private byte loadclassdata (string name) ? inputstream

21、is = null;? byte data = null;? bytearrayoutputstream baos = null;/? system.outprintin(n? classloader:n + + n try toload11);9979797 f ry/aaaux»-fa-name = name . replace (11.11 z 11 n );is = new filelnputstream(new file(path + name +classfiletype);? baos = new bytearrayoutputstream ();?

22、 int ch = 0;? while (-1 != (ch = is.read()? baos.write(ch);? ? date = baos.tobytearray();? ? catch (filenotfoundexception e) /? e.printstacktrace();return null;9799999? catch (ioexception ioe) ioe printstacktrace()99797? finallytryisclose();9999999999q9999baosclose();catch (exception e2)9979797? ret

23、urn data;? ? public static void main (sti?ing args) throws exception ? /wipaipi 3oo0-? myclassloader father = new myclassloader (11 father11); ? father.setpath(home + nsyslibh;myclassloader child = new myclassloader(father,fchildh);? child. setpath (home + ,fextlf);myclassloader user = new myclasslo

24、ader ( nuser,f); user .setpath (home + ,fusrn);system, out printin (,f /2令总e场嵐三10壬卩 traverseparent(child);test parentifchildsystem out.printin(n);/2aeo6o0test load begin fromtesttest(child); /eoauauioanamespace? testnamespace(user);system out.printin ( n,f)；? ? public static void traverseparent(clas

25、sloader loader) throws exception? if (loader = null) return;? system.out.printin(ntravase classloader:n + loader.tostring();? while (loader.getperento ! = null) ? system.out.printin(loadergetparent();? loader = loader.getparento;? ? ? public static void test(classloader loader) throws exception ? cl

26、ass<?> clazz =loader. loadclass (,fcom. ice . class loader. loadedclass11);? object object = clazz.newlnstance();? ? public static void testnamespace (classloader loader) throws exception? c"ss<?> clazz = loader. loadclass ( ncom< ice classloader loadedclass11);? object object =

27、clazz.newlnstance();try? loadedclass lc = (loadedclass) object;? catch(exception e) ? e-printstacktrace();? ±»%oo0aaloadedclasspa(|r dae?ia£°/±»w60aapackage com.iceclassloader;public class loadedclass ? public loadedclass()? sys tem. out. pri ntl n ( "loededcldss i

28、s loaded by: 11 ? + this.getclass().getclassloader();? (d.exraeuchild%6o0»ar idfatherddooof-edfatherpaoooaiaiaduxad 6|paclassia%t)£->od»a6e 55%6o04-father0dd(|o6|pa,/i6o01nx4-(fatherd2»a!»6eappclassloaderofext classloadereoddooof-paaodo圧三2 好0%i 入応丹oo0£ 创 00°6

29、87;衣0%。3 注o%0dd%oo0)test parenttravase classloader:childfathersun.mlsclauncher$appclassloader1372alasun.misc.launcher$extclassloaderad3ba4test load begin from child loadedclass is loaded by: fatherpifatherpaoooaaiaaddolpaclassi 入»£。6滋»olchild%0dd%oo0test parenttravase classloader:chil

30、dfathersun.misc.launcher$appclassloader1372alasiin.misc launcher $extclassloaderad3 bai4test load begin from childloadedclass is loaded by: child(2).auauo!4a>oaeoeoumyclassloadereiylili 即 a (o'oaddaaodo/aaaiodoo 。0卩入)£勺0loadedclasseoeuser%6d02e4-eu%6d0pa£-iappclassloader%6d04-euser

31、%000辰卩入"000亦£t总陆必000亦000必恥myclassloaderll5- ux6%6d0-j-usereu1/46d0paloadedclassaa£-'dumyclas sloaderod3eoepay» loadedclassaie±%i»a3oioegiaziio£°test namespaceloadedclass is loaded by:exception in thread nmainn javalang.noclassdeffounderror: com/ice/classlo

32、ader/loadecaused by:at com.ice.classloader.myclassloader.testnamespace(myclassloade工java:129) at com. ice . classloader .myclassloader .main (myclaissloader1 java: 107):java lang classnotfounciexcepmn: com. ice . classloader . loadedclass j ava .net .urlclassloader$l run (urlclassloaideh .java: 200)

33、at java . security .accesscontroller . doprivileged (nat;* pmhod) at j ava net urlclassloader f indclass (urlclmssloaideh .java: 188) at j ava lang classloader loadclass (clatssloade工.java: 307)at sun.misc.launcher$appclassloader.loadclass(laxincher.java:301) at java.lang.classloader.loadclass(class

34、loaderjava:252)at java.lang.classloader.loadclassinternal(claissloader.java:320)oopo aoyeq30eoep ay» loadedclassaap aao»ddtry loadedclass lc = (loadedclass) object;(catch (exception e) (3).oedde±°uaaeif-iappclassloadera-iaadp±(eq6%6o0d»56com.ice.classloader.virus5aaa(ia

35、classia,/4|)£-iaaxattaker%6604-16«»a1/i6o0da5dvirusaa£->20o|je%aiacom.ice.classloaderpao»2-d£-'4aaateda»nejcom.ice.classloader0iiia±»daeiaapa-aiee,*it>j£p«6e6ue,it>,4i2ee±£-»6e6u>av irusaaoeattackerooo-qappclassloa

36、derl4660£-i1e(|6myclassloadereu±£»n3e6±pa-aiel/6«»a±»xed1j£package com.iceclassloader;public class virus ? publie virus()? system.out.println(“virus is loaded by: n ? + this getc：l3ss() getclassloader ();? myclassloader cl = (myclassloader)this.getcl

37、ass()getclassloader();? system, out pri nt in (11 secret is : n + cl. secret); ? myclassloader6eappclassloadereii,4660£-i(f0virus6eoa»§xdt da(ja%6d04-attackereu% 6d0£-ieae»appclassloadereqattacker pa>5146d0£-%zmyclassloadedvirusie%u£-m«6e6uadb2»e(；6ebd

38、»id %6d0eu%6d0£->,4z2»e66ui-id»56dedde±°u£-ia(；axvirus(|dmyclassloaderpaeu±£»n3e6±-aieeuippublic class myclassloader extends classloader ? protected int secret = -1;/.? public static void main(string args) throws exception ?4 000-r i boot st

39、rap classloader? myclassloader loader = new myclassloader (null, ,floader,f); ? loader. setpath (home + ,fusrh);? myclassloader attacker = new myclassloader (11 attacker,f);? attacker.setpdth (home + hattdckerw);? system.out.printin(myclassloader1s classloader:h + myclassloader.class.getclassloader(

40、);? sys tem. ou t .pi: in tin ( ”testparent,f);? /2色总<5»»场660庄三10工卩test in-package? traverseparent(attacker);? system.outprintw access,f);? testvirus(attacker);? ? public static void traverseparent(classloader loader) throwsexception? if(loader = null) return;? system.out.printin(htrmvm

41、se classloader:n + loader.tostring();? while(loadergetpurent()!= null) ? system.out.printin(loadergetparent();? loader = loader.getparent();? public static void testvirus (classloader loader) throws exception ? class<?> clazz =loader. loadclass ( ncom< ice classloader . virus11);? object ob

42、ject = clazz.newlnstance();? ? myclassloader1s classloader:sun.misclauncher$appclassloader1372alatest parent travase classloader:attackersun.mlsclauncher$appclassloader1372alasun.misclauncher$extclassloaderad3ba4test in-package accessvirus is loaded by: sim.misclauncher$appclassloader1372alaexceptio

43、n in thread nmainn javalangclasscastexc己ption: sun.mlsclauncher$appclassl at com.ice.classloader.virus.<init>(virus.java:8)at sunreflect.nativeconstructoraccessorlmpl.newinstanceo(naxive method)at sun reflect. nativeconstructoraccessorlmpl newlnstance (neidvecons匸rue匸ozac at sunreflect.delegat

44、ingconstructoraccessorimplnewlnstance(delegatingconst; at java.lang.reflect.constructor.newlnstance(constructorjavai:513) at javalangclassnewinstanceo(class.java:355)at java. lang. class .newlnstance (class javai: 308)at com.ice.classloader.myclassloader.testvirus(myclassloadei;java:120)at com. ice

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50、4-6asecuritymanagerpacheckread()!40ddaeieippapef0public fileinputstream(file file) throws filenotfoundexception ? string name = (file != null ? file getp3th() : null); ? securitymanager security = system.getsecuritymanager(); ? if (security != null) ? securitycheckreud(name);? ? if (name = null) ? t

51、hrow new nullpointerexception();? ? fd = new filedescriptor();? fd incrementandgetusecount();? open(name);? checkread()!4 ooat x-?p afilepermissionia2ieyp 4-6acheckpermission()public void checkread(string file) checkpermission(new filepermission(file,securityconstants.file_read_action);jdk 1.2°

52、3e±%°&£1 汩 00 电 © 入 checkpermission (permission perm)°icheckpermission(permission perm, object context)a0dden>i2e£aodpermiaqeq6ozdd2ux-reiidedapaeil>£e9java. io.filepermissiono j °/usr/indata.txti±e6joreadj±2ux-bj£checkpermission()ep%e

53、eldu(|6p±(oib3i|ja!4-'o »!/20ddoa»ao»5daie0d»%3accesscontrolcontext£y 即 moa 圧 acheckpermission()!4publie static void checkpermission(permission perm) ? throws accesscontrolexception ? /system.err.printin(ncheckpermission n+perm);? /thread.currentthread()dumpstack();

54、? if (perm = null) ? throw new nullpointerexception ( npermission can 11 be null11);? accesscontrolcontext stack = getstackaccesscontrolccmtqxt(); ? / if context is null, we had privileged system code on the stack. ? if (stack = null) ? /.debug话0? return;? accesscontrolcontext acc = stack.optimize()

55、;? acc.checkpermission(perm);? checkpermission()»az6j/2- *|jad»(|¥idd»px±eau(,4i2ej/4-'eu6uaa|ja±£»n6de'ip£ -<contexteqd»5dprotectiondomaineyxe)£-'p±6dp!d»>da»6de，if>pad»dj%i»aax3od»5daccessc on

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58、iafalsej£?dljprotectiondomain(/eapermissioncollection)od£-> «0dde it>%-°iau impliesopaadff-iep'/ieeifeoupermissioncollectionddieau+fodeiiopo dpaeip£-ip6aimplies()adt7eae(；n%b6d(|ld6|jaa!eeipi£public void checkpermission(permission perm) ? throws accesscontrolexception? ? ii.