社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 9086阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* cNX0.7Ls  
**SiteFileFetch.java QEavbh^S  
*/ {x+"Ru~7,  
package NetFox; %|3I|'%Y  
import java.io.*; 4TBK:Vm5  
import java.net.*; q]-CTx$  
M%3 \]&  
fcuU,A  
public class SiteFileFetch extends Thread { .)7r /1o  
Xy74D/ocui  
`+4>NT6cu9  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^&AhW m7\  
long[] nStartPos; //开始位置 = }&@XRLJ  
long[] nEndPos; //结束位置 jL|y4  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 5,>Of~YN  
long nFileLength; //文件长度 \,w*K'B_Y  
boolean bFirst = true; //是否第一次取文件 Y\.d s%G  
boolean bStop = false; //停止标志 aX oD{zA  
File tmpFile; //文件下载的临时信息 ]kN<N0;\d  
DataOutputStream output; //输出到文件的输出流 bN ,>,hj  
T,Bu5:@#  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) hdw-gem{?  
public SiteFileFetch(SiteInfoBean bean) throws IOException -`iXAyr)m  
{ YpAJ7 E|7  
siteInfoBean = bean; ,~R`@5+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); d$3;o&VUNI  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); g1je':  
if(tmpFile.exists ()) |M*jo<C  
{ )YDuq(g&  
bFirst = false; RG'Ft]l92N  
read_nPos(); yzvNv]Z'*  
} fQ\nK H~  
else fkprTk^#  
{ p)t1] <,Of  
nStartPos = new long[bean.getNSplitter()]; D# $Fj  
nEndPos = new long[bean.getNSplitter()]; BZ]6W/0  
} {*=+g>R gD  
UBmD 3|Zo  
re\@v8w~  
jm-J_o;}z6  
} QF  P3S(  
*H"IW0I  
gaK m`#  
public void run() @} nI$x.  
{ j|`6[93MG  
//获得文件长度 |Ef\B] Ns  
//分割文件 A9*( O)  
//实例FileSplitterFetch [j6EzMN  
//启动FileSplitterFetch线程 4Y):d!'b  
//等待子线程返回 yGNZw7^(  
try{ uCc.dluU  
if(bFirst) ;XJK*QDN  
{ Q}KNtNCpx  
nFileLength = getFileSize(); 5E~?hWAv  
if(nFileLength == -1) Dq#/Uw#  
{ sr0.4VU1  
System.err.println("File Length is not known!"); F{#m~4O  
} *K9I+t"g  
else if(nFileLength == -2) U4DQ+g(A  
{ S$CO T)7  
System.err.println("File is not access!"); z7[TgL7  
} >&@hm4  
else ~?V+^<P  
{ E8TJ*ZU  
for(int i=0;i<nStartPos.length;i++) 1v)X]nW  
{ xW$F-n  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 9Tgl/}q)  
} [m9Pt]j@  
for(int i=0;i<nEndPos.length-1;i++) ]L'FYOfrpx  
{ /`M> 3q[  
nEndPos = nStartPos[i+1]; hEO#uAR^Z  
} 4H7 3a5f  
nEndPos[nEndPos.length-1] = nFileLength; 9;Z2.P"w  
} dXkgWLI~  
} "4VC:"$f  
| HkLl^  
M*DFtp<  
//启动子线程 x=+R0ny  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oYYns%r}{  
for(int i=0;i<nStartPos.length;i++) _xg4;W6M=  
{ =j)y.x(  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @S/PB[%S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q|E0Y   
nStartPos,nEndPos,i); [x {S ,?6  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z_ Gb9  
fileSplitterFetch.start(); w#?@ulr]d  
} /UJ@e  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $ae*3L>5M  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9n$0OH /q  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", '64&'.{#>r  
nEndPos = " + nFileLength); >28.^\?H4  
// fileSplitterFetch[nPos.length-1].start(); 4$~]t:n  
RwH<JaL:  
|{#=#3X  
//等待子线程结束 T5mdC  
//int count = 0; .YvE  
//是否结束while循环 }yCw|B|a  
boolean breakWhile = false; |E\0Rv{H3  
aZ$$a+  
3pxm0|  
while(!bStop) sZ,MNF8i  
{ _n.2'  
write_nPos(); "W_C%elg  
Utility.sleep(500); _1z|QC  
breakWhile = true; 4dDDi,)U  
F^5<o  
u3!aKXnv<  
for(int i=0;i<nStartPos.length;i++) ^y.e Fz  
{ S.;>:Dd[K  
if(!fileSplitterFetch.bDownOver) 9m2_zfO[ w  
{ >".,=u'  
breakWhile = false; l2DhFt$!=  
break; )4d)G5{  
} r]x;JBy  
} hcQvL>  
if(breakWhile) 4<S*gu*W  
break; >*xa\ve  
f%LzWXA  
u$%>/cv  
//count++; -+1it  
//if(count>4) Da)rzr|}>3  
// siteStop(); M@a?j<7P,m  
} s52c`+  
B;M{v5s~]  
39;Z+s";  
System.err.println("文件下载结束!"); =*q|568  
} lVywc:X  
catch(Exception e){e.printStackTrace ();} 4\HB rd#P  
} h&7]Bp  
=<-tD<  
55vpnRM  
//获得文件长度 '1)BZ!  
public long getFileSize() -e=p*7']  
{ LGN,8v<W(  
int nFileLength = -1; /K mzi9j+  
try{ (wmMHo|  
URL url = new URL(siteInfoBean.getSSiteURL()); X\SZ Q[gN  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !GkwbHr+p  
httpConnection.setRequestProperty("User-Agent","NetFox"); im&E \`L7  
S~1>q+<Q  
k^q}F%UV  
int responseCode=httpConnection.getResponseCode(); B;'Dh<J1  
if(responseCode>=400) 15Vb`Vf`N  
{ { 7y.0_Y  
processErrorCode(responseCode); (7RxCo=X  
return -2; //-2 represent access is error 9I>+Q&   
} p*10u@,  
rs01@  
9X8{"J  
String sHeader; I xT[1$e  
_A*5BAB:h(  
D_GIj$%N[  
for(int i=1;;i++) U;n$  
{ @%L4^ms  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xq:.|{HUk  
//Utility.log(in.readLine()); DG8LoWZ  
sHeader=httpConnection.getHeaderFieldKey(i); !Gu,X'#Ab  
if(sHeader!=null) I__|+%oC  
{ v}hmI']yf  
if(sHeader.equals("Content-Length")) v*%#Fp,g8  
{ hd~X c  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v\*43RL  
break; jsS xjf;O  
} qr%9S dvx  
} "J]_B  
else BM*9d%m^  
break; #LlHsY530N  
} >:M3!6H_~{  
} R}F0_.  
catch(IOException e){e.printStackTrace ();} .op: 2y9]  
catch(Exception e){e.printStackTrace ();} hkw;W[ZWa  
G l+[ |?N  
kLVf}J~?  
Utility.log(nFileLength); _Zya GDv  
uhL+bj+W  
H4LZNko  
return nFileLength; JicAz1P1W  
} hXi^{ntw,  
p<>%9180!F  
<,d.`0:y  
//保存下载信息(文件指针位置) $x5P5^Y  
private void write_nPos() s z  
{ 2wE?O^J  
try{ ]]{$X_0n  
output = new DataOutputStream(new FileOutputStream(tmpFile)); D3V5GQ\=  
output.writeInt(nStartPos.length); W B)<B  
for(int i=0;i<nStartPos.length;i++) WO W4c&  
{ FL!W oTB  
// output.writeLong(nPos); 5T;M,w6DV  
output.writeLong(fileSplitterFetch.nStartPos); ;cl\$TDL  
output.writeLong(fileSplitterFetch.nEndPos); _^Lv8a3(O  
} `_sc_Y|C!  
output.close(); R6HMi#eF  
} ?Y2ZqI  
catch(IOException e){e.printStackTrace ();} 9Vz1*4Ln  
catch(Exception e){e.printStackTrace ();}  t4pc2b  
} Ddde, WJA  
iph>"b$D  
Z^,C><Yt  
//读取保存的下载信息(文件指针位置) c%v[p8 %  
private void read_nPos() GHeJpS  
{ jr{C/B}  
try{ $$~x: iN  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !7!xJ&/V  
int nCount = input.readInt(); 8;;!2>N  
nStartPos = new long[nCount]; uZ( I|N$  
nEndPos = new long[nCount]; L+Yn}"gIs  
for(int i=0;i<nStartPos.length;i++) ]kq{9b';  
{ a'f"Zdh%w  
nStartPos = input.readLong(); . $uvQpyh  
nEndPos = input.readLong(); o^;$-O!/  
} ;T~]|#T\6  
input.close(); ^Bn)a"Gd  
} $.kP7!`:,  
catch(IOException e){e.printStackTrace ();} yC !`6$  
catch(Exception e){e.printStackTrace ();} wXp A1,i  
} IW3ZHmrpA  
]&\HAmOQS  
xaSvjc\  
private void processErrorCode(int nErrorCode) 5bM/ v  
{ Zpg/T K  
System.err.println("Error Code : " + nErrorCode); -_Pd d[M  
} wEENN_w  
gO%#'Eb2  
,ii*[{X?  
//停止文件下载 "Wr5:T-;  
public void siteStop() c4ptY5R),  
{ $A"kHS7T  
bStop = true; KJ<7aZ  
for(int i=0;i<nStartPos.length;i++) y0cHs|8  
fileSplitterFetch.splitterStop(); BJ!b LQ  
?|'+5$  
B1T:c4:N  
} 84^ '^nd  
} SA&0f&07i  
//负责部分文件的抓取 F>Rz}-Fy  
**FileSplitterFetch.java x@I*(I  
*/ <l]P <N8^  
package NetFox; py.lGywb_  
/%9D$\  
K: g_M  
import java.io.*; e*p7(b-  
import java.net.*; zWpJ\/k~  
zbK=yOIOd  
/^^t>L  
public class FileSplitterFetch extends Thread { Gm;)Om_  
Aifc0P-H  
\Km!#:  
String sURL; //File URL e5KsKzu a  
long nStartPos; //File Snippet Start Position $X8(OS5d'  
long nEndPos; //File Snippet End Position ,#[0As29u  
int nThreadID; //Thread's ID tFt56/4  
boolean bDownOver = false; //Downing is over zY~  
boolean bStop = false; //Stop identical 5vs~8|aRo  
FileAccessI fileAccessI = null; //File Access interface nf& P Dv1  
;q]Jm  
C,7d  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z"PPXv-<jY  
{ 0X@!i3eu  
this.sURL = sURL; b/'{6zn  
this.nStartPos = nStart; 3~Od2nk(x  
this.nEndPos = nEnd; uc!j`G*]  
nThreadID = id; S9R(;  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fe PH=C  
} X.hU23w  
:)VO,b~r  
$Llv6<B  
public void run() -SZXUN  
{ ,?k[<C  
while(nStartPos < nEndPos && !bStop) 7S$Am84%  
{ eqbQ,, &  
>)*'w!  
\MBbZB9@  
try{ 2g5i3C.q$  
URL url = new URL(sURL); HA&7 ybl  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $U%M]_  
httpConnection.setRequestProperty("User-Agent","NetFox"); Z- |.j^n  
String sProperty = "bytes="+nStartPos+"-"; |S.G#za  
httpConnection.setRequestProperty("RANGE",sProperty); I^"ou M9}Q  
Utility.log(sProperty); /aS=vjs  
D\|$ ! i}  
 m=D2|WA8  
InputStream input = httpConnection.getInputStream(); yO*~)ALb+  
//logResponseHead(httpConnection); cb!mV5M-g  
TI4#A E  
,5oe8\uz  
byte[] b = new byte[1024]; "1 O!Ck_n  
int nRead; %@tKcQ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O ]o7  
{ MB.\G.bV  
nStartPos += fileAccessI.write(b,0,nRead); &_Kb;UVRj  
//if(nThreadID == 1) j6v|D>I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :5Vk+s]8  
}  [U9b_`  
xi['knUi2-  
J1OZG6|e  
Utility.log("Thread " + nThreadID + " is over!"); MmiC%"7wt  
bDownOver = true; ^mxOQc !  
//nPos = fileAccessI.write (b,0,nRead); ZoX24C'  
} m>yb}+  
catch(Exception e){e.printStackTrace ();} S3#NGBZ/  
} B1<:nl  
} D.d(D:  
ZrY #B8  
p}q27<O*/  
//打印回应的头信息 $ N`V%<W  
public void logResponseHead(HttpURLConnection con) 9U[Gh97Sf  
{ ldp x,  
for(int i=1;;i++) <xM$^r)  
{ DfYOGs]@  
String header=con.getHeaderFieldKey(i); 3ARvSz@5  
if(header!=null) Gk_%WY*  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z] ?Tx2|7  
Utility.log(header+" : "+con.getHeaderField(header)); N(i%Oxp1  
else HYVSi3[  
break; MKVz'-`u  
} t Gt/=~n9  
} iMG)zPj  
%smQ`u|  
^(z7?T  
public void splitterStop() vJZ0G:1  
{ 8vQGpIa,  
bStop = true; \H<gKZquR  
} >,c$e' h  
-7MR2)U  
wEju`0#;  
} O-m=<Fk> D  
8Aq [@i  
5)h#NkA\J  
/* &L7u//  
**FileAccess.java C]S~DK1  
*//文件访问(定位,写) B ~u9"SR.  
package NetFox; $t*>A+J  
import java.io.*; |-Rg].  
=$bJ`GpJ  
1{6BU!  
public class FileAccessI implements Serializable{ oCtg{*vp  
$cl[Qcw  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nW)-bAV<  
RandomAccessFile oSavedFile; =^liong0  
long nPos; lMkDLobos  
.CJQ]ECl7p  
Xae0xs  
public FileAccessI() throws IOException d)@Hx8  
{ EY3x o-H  
this("",0); 'I$-h<W  
} SCwAAE9s]  
pe^hOzVv  
(EW<Ggi  
public FileAccessI(String sName,long nPos) throws IOException u&4CXv=  
{ mCM7FFl I  
oSavedFile = new RandomAccessFile(sName,"rw"); b1+6I_u.  
this.nPos = nPos; H~Z$pk%  
oSavedFile.seek(nPos); qY,z,o AF  
} ~nit~ ;  
`As| MYv  
D$ X9xtT  
public synchronized int write(byte[] b,int nStart,int nLen) 7  s+j)  
{ un*Ptc2%  
int n = -1; (pBPf  
try{ jbQ N<`!  
oSavedFile.write(b,nStart,nLen); XKp$v']u  
n = nLen; E`E$ }iLs  
} bBx.snBK  
catch(IOException e) !Cqm=q{K  
{ Wp2W:JX:  
e.printStackTrace (); @|I:A  
} R$>]7-N}  
@ P:b\WCI  
IE;Fu67wi  
return n; 2bJqZ,@  
} P:~X az\F  
M't~/&D#  
euxkw]`h6  
} :+ASZE.  
Mn)>G36(  
@B.;V=8wJ  
/* 8PN/*Sa  
**SiteInfoBean.java | aAu 4   
*/ :ik$@5wp  
package NetFox; VV_Zrje  
l ~bjNhk  
=D&xw2  
public class SiteInfoBean { ~Onj| w7  
Sf_q;Ws  
w@K4u{|  
private String sSiteURL; //Site's URL /6?A#%hc  
private String sFilePath; //Saved File's Path o0yyP,?yh  
private String sFileName; //Saved File's Name @M]uUL-ze  
private int nSplitter; //Count of Splited Downloading File O~p@87aq  
YwbRzY-#F  
t>f61<27eB  
public SiteInfoBean() m=s aUhI*9  
{//nSplitter的缺省值为5 g Kp5*  
//default value of nSplitter is 5 s=[Tm}[  
this("","","",5); Lg;b17  
} ,^Cl?\9"  
su?{Cj6*  
cpIFjb>u{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p3m!Iota  
{ mbf'xGO  
sSiteURL= sURL; ;-aF\}D@n  
sFilePath = sPath; /]xu=q2  
sFileName = sName; sl5y1W/]]  
this.nSplitter = nSpiltter; FJ/>=2^B  
PIZnzZ@Z;  
"7]YvZYu0  
} >DFpL$oP  
n;Nr[hI  
*qX!  
public String getSSiteURL() p"xti+2,  
{ o {W4@:Ib  
return sSiteURL; R*"31&3le4  
} Qkk3>{I  
 +*W9*gl  
3 s@6pI  
public void setSSiteURL(String value) ^)JUl!5j]C  
{ @ij8AGE:  
sSiteURL = value; oVD)Fb%[i9  
} u~uR:E%'C  
z%4E~u10  
{Df97n%h;  
public String getSFilePath()  #  
{ 1 #zIAN>  
return sFilePath; N WSm  
} )aV\=a |A  
"mbjS(-eg  
}NH\Q$IU  
public void setSFilePath(String value) fXL&?~fS  
{ QU#u5sX A  
sFilePath = value; wgN)*dpuI  
} P#8+GN+bF  
aEO``W  
QNN*/n  
public String getSFileName() n+sV $*wvS  
{ wqB 5KxO  
return sFileName; 3Y;<Q>roT  
} 9_$i.@L 1  
T%[&[8{8  
yLC5S3^1\"  
public void setSFileName(String value) &J]|pf3m  
{ 4 6yq F  
sFileName = value; [Iwb7a0p  
} m L#%H(  
lmsO 6=I4F  
35;UE2d)<  
public int getNSplitter() {?!0<0  
{ /k$H"'`j4  
return nSplitter; Wzn!BgxRr  
} JU6PBY~C'  
{vp|f~}zTw  
A`#/:O4|f  
public void setNSplitter(int nCount) 7Gos-_s  
{ !nm[ZrS P  
nSplitter = nCount; 5W Z9z-6  
} nDFF,ge;a#  
} ms(Z1ix^  
o4[  
+zl2| '  
/* h/LlH9S:!  
**Utility.java ^(Y}j8sj  
*/ \68x]q[  
package NetFox; Dc1tND$X3g  
2 cB){.E  
A89n^@  
public class Utility { ]* #k|>Fl  
Np.] W(  
rfz\DvV d  
public Utility() M*+MhM-  
{ tc|`cB3f  
?<*mIf:?  
RaT_5PH~g  
} hja;d1yH  
kPuI'EPK  
//线程睡眠 ~Z{IdE  
public static void sleep(int nSecond) ~xp(k  
{ SU` RHAo  
try{ $-=QTX  
Thread.sleep(nSecond); TJ5g? #Wul  
} 7CGxM  
catch(Exception e) G1!yPQa7d  
{ 34Fc oud);  
e.printStackTrace (); Bd8{25{c  
} dF`\ewRFn  
} +A!E 6+'  
c; MF  
//日志 pA%Sybw+  
public static void log(String sMsg) + Cf  
{ en5sqKqh+  
System.err.println(sMsg); q!qOy/}D  
} Ir,3' G  
-|FSdzvg  
@[2Go}VF  
public static void log(int sMsg) b3vPGR  
{ fOHgz ,x=  
System.err.println(sMsg); 2 omKP,9,2  
} AB:JXMyK  
} O^2@9 w  
hoOT]Bsn  
M'gL_Xsei  
/* T, z80m}  
**TestMethod.java 5gg Yg $  
*/ b@> MA  
package NetFox; c1wP/?|.>  
FG6bKvEQm^  
nYvx[ zq?^  
public class TestMethod { 8M~^/Zc  
}~akVh`3  
-".q=$f  
public TestMethod() |Y9mre.Y;  
{ ///xx/weblogic60b2_win.exe Qm >x ?  
try{ =.Hq]l6+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %77X/%.Y  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z2 m(<zb  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6F)^8s02h  
fileFetch.start(); $GI jWlAh  
} Pw :{  
catch(Exception e){e.printStackTrace ();} f)b+>!  
Dus [N< w  
jMAZ4M  
} sx]kH$  
?nwFc3qw  
[#3*R_#8R  
public static void main(String[] args) Rt6(y #dF  
{ \I[f@D-J  
new TestMethod(); nRSiW*;R  
} kLfk2A;'i  
} Y+kfMAv  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八