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
  • 7939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
/* C(}Kfi@6N  
**SiteFileFetch.java UDb  
*/ V}Pv}j:;  
package NetFox; Rz33_ qA  
import java.io.*; Fh.Z sPn,m  
import java.net.*; `>`{DEDx{5  
EHt(! ;?q  
&y~GTEP  
public class SiteFileFetch extends Thread { S|_lb MZM  
ZMch2 U8  
3UJSK+d\  
SiteInfoBean siteInfoBean = null; //文件信息Bean 7gt%[r M  
long[] nStartPos; //开始位置 $oZV 54  
long[] nEndPos; //结束位置 gn[h:+H&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N0fmC*1-  
long nFileLength; //文件长度 >n>gX/S<C  
boolean bFirst = true; //是否第一次取文件 6!RK Zj)  
boolean bStop = false; //停止标志 8 HdjZ!  
File tmpFile; //文件下载的临时信息 ,m)YL>k  
DataOutputStream output; //输出到文件的输出流 q?# w%0}  
z!^3%kJJ>  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) T2 V(P>E  
public SiteFileFetch(SiteInfoBean bean) throws IOException /fxv^C82yv  
{ -yY]0  
siteInfoBean = bean; lI+KT_|L  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Y IVN;:B.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Ce PI{`&,  
if(tmpFile.exists ()) Mey=%Fv  
{ ~93+Oxg  
bFirst = false; 6Ou[t6  
read_nPos(); M_\)<a(8  
} Xyw;Nh!!d  
else 5Veybchy "  
{ @34CaZ$k  
nStartPos = new long[bean.getNSplitter()]; &P>a  
nEndPos = new long[bean.getNSplitter()]; R?l={N=Wf  
} YuzgR;Z  
L%4Do*V&  
Mj:=$}rs^  
{c=H#- A  
} &fwb?Vn4  
>\ PNKpn{  
y!kM#DC^  
public void run() |z.Ov&d4)(  
{ zA&]#mc  
//获得文件长度 WO{9S%ck  
//分割文件 E XQ 3(:&  
//实例FileSplitterFetch $-_@MT~  
//启动FileSplitterFetch线程 Ga $EM  
//等待子线程返回 @ {8x L  
try{ vce1'aW  
if(bFirst) 3HB(rTw  
{ MJ`BlE,Fmb  
nFileLength = getFileSize(); zY\MzhkX,  
if(nFileLength == -1) | PzXN+DW  
{ 6s&%~6J,  
System.err.println("File Length is not known!"); gz`P~7-w:  
} _,E! <  
else if(nFileLength == -2) BxGz4  
{ c`!8!R  
System.err.println("File is not access!"); `xu/|})KI  
} 08;t%[R  
else i^6g1"h  
{ <@H=XEn  
for(int i=0;i<nStartPos.length;i++) X:gE mcXc  
{ AO^c=^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); nV?e(}D  
} j*@EJ"Gm>  
for(int i=0;i<nEndPos.length-1;i++) /Wm3qlv  
{ 4(}V$#^+  
nEndPos = nStartPos[i+1]; (khMjFOg  
} {#uf#J|  
nEndPos[nEndPos.length-1] = nFileLength; kI#yW!  
} y ;T=u(}  
} d i#:KW  
NFlrr*=t>  
%z AN@  
//启动子线程 )\0LxsZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tU(vt0~b  
for(int i=0;i<nStartPos.length;i++) "(SZ;y  
{ |>AHc_:$$  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3']=w@~ O[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lw #vHNf6  
nStartPos,nEndPos,i); aG/L'weR  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aT%6d@g  
fileSplitterFetch.start(); 4Nz]LK%@  
} .eM A*C~n  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (%f2ZNen  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (= ,w$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +#0,2 wR#  
nEndPos = " + nFileLength); ttC+`0+H  
// fileSplitterFetch[nPos.length-1].start(); ~:lN("9OI  
}e0)=*;l  
Zk75GC  
//等待子线程结束 ,[0rh%%j  
//int count = 0; eXZH#K7S#  
//是否结束while循环 A;#GU`  
boolean breakWhile = false; $sR-J'EE!  
4 | DGQ  
MbeO(Q  
while(!bStop) Xw[|$#QKM  
{ XveG#oyiU  
write_nPos(); 6?(vXPpT$  
Utility.sleep(500); \Dn an5H/  
breakWhile = true; Mny mV;y"  
Y'%k G5nF  
G/5]0]SO  
for(int i=0;i<nStartPos.length;i++) m;"dLUb  
{ f1UGDC<p9  
if(!fileSplitterFetch.bDownOver) &nEQ `3~F  
{ by%k*y  
breakWhile = false; Cz1o@ rt  
break; l:rT{l=8*  
} a#:K"Mf.  
} ^zVBS7`J  
if(breakWhile) .|9o`mF7  
break; !]z6?kUK  
S`?cs^?  
gw);b)&mx  
//count++; _f5n t:-  
//if(count>4) B\} B H  
// siteStop(); 5(sWV:_2  
} gzD NMM  
pJ 7="n  
>rb8A6  
System.err.println("文件下载结束!"); 2pQdDbm  
} C [h^bBq  
catch(Exception e){e.printStackTrace ();} +HOHu*D  
} -%#F5br%  
"G3zl{?GP  
8o4?mhqV  
//获得文件长度 S;FgS:;  
public long getFileSize() 8h| 9;%  
{ O'} %Bjl  
int nFileLength = -1; C7lBK<gQ  
try{ %1oG<s  
URL url = new URL(siteInfoBean.getSSiteURL()); $9Yk]~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h16i]V  
httpConnection.setRequestProperty("User-Agent","NetFox"); $5n6C7  
G`" 9/FI7  
96$qH{]Ap  
int responseCode=httpConnection.getResponseCode(); #+,O  
if(responseCode>=400) m=uW:~  
{ 9!06R-h  
processErrorCode(responseCode); O A9G] 8k  
return -2; //-2 represent access is error R8<'m  
} b4HUgW3Ac  
8hx 3pvmk  
g`BtG  
String sHeader; 1-M\K^F  
 + Y  
{a `#O9  
for(int i=1;;i++) P,@ :?6  
{ ?nya;Z-~Hc  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )KPQ8y!d  
//Utility.log(in.readLine()); <(U :v  
sHeader=httpConnection.getHeaderFieldKey(i); &7CAxU;i3  
if(sHeader!=null) m|5yET  
{ M(_1'2  
if(sHeader.equals("Content-Length")) m"CsJ'\ors  
{ 4pfv?!Oj  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5@xl/  
break; ;%H/^b.c  
} K!MIA  
} |tkhsQ-;  
else *j0kb"#  
break; LYv$U;*+  
} hD5G\TR.  
} mSu1/?PS  
catch(IOException e){e.printStackTrace ();} rcWr0q  
catch(Exception e){e.printStackTrace ();} Jm l4EW7  
(\=iKE4#  
OYsG#  
Utility.log(nFileLength); v)a$;P%  
2 Xt$KF,?  
;ESuj'*t  
return nFileLength; C=z7Gk=  
} X_0Ta_u?T  
UmRI! WQl  
k}yUD 0Y  
//保存下载信息(文件指针位置) uS%Y$v  
private void write_nPos() C {GSf`D!T  
{ -`o22G3w  
try{ 8=#J:LeXj  
output = new DataOutputStream(new FileOutputStream(tmpFile)); w9J^s<e  
output.writeInt(nStartPos.length); RI q9wD}4(  
for(int i=0;i<nStartPos.length;i++) xxlYn9ke  
{ "$VqOSo  
// output.writeLong(nPos); @+3@Z?!SZ  
output.writeLong(fileSplitterFetch.nStartPos); i"{ \ >  
output.writeLong(fileSplitterFetch.nEndPos); x3JX}yCX  
} X~ AE??  
output.close(); '<35XjW  
} 1~HR;cTv=  
catch(IOException e){e.printStackTrace ();} }LaRa.3  
catch(Exception e){e.printStackTrace ();} J,bE[52  
} 9ntXLWK7e  
3 oG5E"G  
-R[ *S "  
//读取保存的下载信息(文件指针位置) n' \poB?  
private void read_nPos() g`}+K U  
{ '01ifA^  
try{ ,KMt9 <  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %S<0l@=5`l  
int nCount = input.readInt(); _Co*"hl>2  
nStartPos = new long[nCount]; +s}"&IV%  
nEndPos = new long[nCount]; ,c%>M^d  
for(int i=0;i<nStartPos.length;i++) 7n1@m_7O  
{ )K4A-9pC  
nStartPos = input.readLong(); j(`L)/|O  
nEndPos = input.readLong(); h7( R/Rf  
} p)$DpNL% p  
input.close(); ZPT6 p J  
} Kug_0+gI  
catch(IOException e){e.printStackTrace ();} Fnnk }I}  
catch(Exception e){e.printStackTrace ();} wi]F\ q"Y^  
} :CQ-?mT^LA  
a/Cd;T2  
.7ZV: m  
private void processErrorCode(int nErrorCode) k|^e=I   
{ m{/?6h 1  
System.err.println("Error Code : " + nErrorCode); b|cUKsL5  
} ng-g\&-  
z]NzLz9VfL  
V'";u?h#S  
//停止文件下载 |g3a1El  
public void siteStop() >&|C E2'  
{ _7AR2  
bStop = true; BnLM;5 >  
for(int i=0;i<nStartPos.length;i++) ? (&)p~o  
fileSplitterFetch.splitterStop(); VPB,8zb ]  
bN6FhKg|  
cI9}YSk  
} #)aUKFX  
} iI2 7N'g  
//负责部分文件的抓取 liW0v!jBo  
**FileSplitterFetch.java qeK_w '  
*/ V Q6&7@ c  
package NetFox; <$^76=x,8P  
z*cC2+R}=  
XNwZSW  
import java.io.*; .kl _F7  
import java.net.*; ]*8K4n G  
.Y8z3O  
f_*Bd.@  
public class FileSplitterFetch extends Thread { 1N#KVvK  
8\+Q*7~@i  
Jon<?DQj  
String sURL; //File URL .e $W(}  
long nStartPos; //File Snippet Start Position akuV9S  
long nEndPos; //File Snippet End Position M(l>^N8W8  
int nThreadID; //Thread's ID >Cb[  
boolean bDownOver = false; //Downing is over Vf67gux  
boolean bStop = false; //Stop identical 4,o|6H  
FileAccessI fileAccessI = null; //File Access interface -.8 nEO3  
mCa [?  
YxEc(a"  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K5O#BBX=  
{ zFy0Sz F  
this.sURL = sURL; wzr3 y}fCe  
this.nStartPos = nStart; u? a*bW  
this.nEndPos = nEnd; p#VA-RSUQ|  
nThreadID = id; N|n"JKw)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,4bqjkX5q  
} "T`Q,  
}1ABrbc  
@S/jVXA  
public void run() ;]* %wX  
{ H\OV7=8  
while(nStartPos < nEndPos && !bStop) S H"e x,=  
{ Iv6(Z>pAB  
^f:oKKaAW;  
qSRE)C=)  
try{ (x{6N^J.t  
URL url = new URL(sURL); RR u1/nam  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1LbJR'}  
httpConnection.setRequestProperty("User-Agent","NetFox"); T)"B35  
String sProperty = "bytes="+nStartPos+"-"; n+db#qAj5  
httpConnection.setRequestProperty("RANGE",sProperty); lKo07s6u  
Utility.log(sProperty); z\z mAus  
IXp(Aeb  
qVOlUH  
InputStream input = httpConnection.getInputStream(); _raj b1!  
//logResponseHead(httpConnection); `K.2&6xc  
0B0Uay'd_  
lx8@;9fLy  
byte[] b = new byte[1024]; B'( /W@  
int nRead; O7p>"Bh  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p`@7hf|hm  
{ |K(j}^1k  
nStartPos += fileAccessI.write(b,0,nRead); ~_SoP  
//if(nThreadID == 1) H"_ZqEg  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :zXkQQD8`  
} v(+9&  
1l$c*STK  
;++CMTza]  
Utility.log("Thread " + nThreadID + " is over!"); #&JhA2]q  
bDownOver = true; j[z o~Y4z  
//nPos = fileAccessI.write (b,0,nRead); #HjiE  
} Ww9%6 #i t  
catch(Exception e){e.printStackTrace ();} &,pL3Qos  
} KLpe!8tAe  
} Xx~za{p  
3snr-)   
%?gh;? GD  
//打印回应的头信息 *Uvh;d{  
public void logResponseHead(HttpURLConnection con) Zi&qa+F  
{  `Pa)H  
for(int i=1;;i++) PNwXZ/N%  
{ {H FF|Dx  
String header=con.getHeaderFieldKey(i); (1`z16  
if(header!=null) ['p%$4i$  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C5Fk>[fS  
Utility.log(header+" : "+con.getHeaderField(header)); |D `r o  
else 86bl'FdKS  
break; L*TPLS[lh  
} OR4ZjogzY  
} zmV5k  
L0\97AF  
pBW|d\8  
public void splitterStop() #/u%sX`#y  
{ &/K:zWk3mx  
bStop = true; 7X \azL  
} ! &f(X s  
vYT%e:8)q  
Nqih LUv  
} E'|@hL-jn  
CAGaZ rx  
.G"UM>.}d  
/* @<$-*,  
**FileAccess.java ig Mm.1>  
*//文件访问(定位,写) W2CCLq1(  
package NetFox; :JBvCyj4PE  
import java.io.*; Qqt<  
%nU8 Ca  
5(@P1Bi  
public class FileAccessI implements Serializable{ ( Z-~Eh  
5r;M61  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ok7i^-85  
RandomAccessFile oSavedFile; i *W9 4  
long nPos; 8*sZ/N.  
ich\`j[i  
cR 0+`&  
public FileAccessI() throws IOException K OZHz`1!  
{ {fi:]|<1h  
this("",0); ES~ykE  
} %i!&Fr  
&&Sl0(6x[T  
{VWX?Mm  
public FileAccessI(String sName,long nPos) throws IOException #b[B$  
{ EZ+_*_9  
oSavedFile = new RandomAccessFile(sName,"rw"); GEr]zMYG[A  
this.nPos = nPos; 'g<0MOq{  
oSavedFile.seek(nPos); JGS4r+   
} mlolSD;7  
lM1Y }  
^4Ta0kDn  
public synchronized int write(byte[] b,int nStart,int nLen) D8u_Z<6IjI  
{ V~rF`1+5N  
int n = -1; \}O'?)(1  
try{ ZJL[#}*  
oSavedFile.write(b,nStart,nLen); . }QR~IR'  
n = nLen; gAcXd<a0  
} X@$x(Zc  
catch(IOException e) %]/O0#E3Kz  
{ &yFt@g]  
e.printStackTrace (); ~(2G7x)  
} &"vh=Z-  
"Dbjp5_  
wyqXD.o f  
return n; JFw<Po,MEa  
} k_)H$*  
^rd]qii"  
1b)^5U ;  
} :OC`X~}Rc  
'%&i#Eb  
q4)8]Y2  
/* V#!ftu#c?  
**SiteInfoBean.java \ "193CW!  
*/ Vj^<V|=  
package NetFox; AplXl=  
vh8{*9+  
Eeem y*U  
public class SiteInfoBean { vAW+ ,Rfj  
,(0q  
cC'{+j8-a  
private String sSiteURL; //Site's URL Og8:  
private String sFilePath; //Saved File's Path h#K863  
private String sFileName; //Saved File's Name :'-FaGy  
private int nSplitter; //Count of Splited Downloading File vas   
Xj:?V;  
]d]tQPEU  
public SiteInfoBean() D'y/ pv}!  
{//nSplitter的缺省值为5 s'yA^ VPf  
//default value of nSplitter is 5 $xT'cl/IH  
this("","","",5); !"\UT&  
} LD]>_P83  
4u;db_gX  
cX$ Pq  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) # [c`]v  
{ ;IX3w:Aw  
sSiteURL= sURL; SWujj,-[  
sFilePath = sPath; q.L0rY!  
sFileName = sName; #S+GI!  
this.nSplitter = nSpiltter; cE S3<`[K  
3cK`RM `  
8NLTq|sW  
} }a= &o6=  
/`yb75  
=k]RzeI  
public String getSSiteURL() <5*cc8  
{ $Bd{Y"P@6  
return sSiteURL; 9)={p9FZY  
} I>X_j)  
\D8d!gr  
K9Dxb  
public void setSSiteURL(String value) {3Z&C$:s  
{ R3;GMe@D#  
sSiteURL = value; Fxwe,  
} '\ec ,&4Z  
"y@B|  
|sWH!:]49  
public String getSFilePath() "7_6iB&@<  
{ yE3g0@*  
return sFilePath; mO$]f4}  
} &E.ckWf  
z@hlN3dg  
Yrp WGK520  
public void setSFilePath(String value) qv<[f=X9|  
{ 6AgevyVG  
sFilePath = value; BwO^F^Pr?k  
} f`@$ saFD  
^` N+mlh  
BR5r K  
public String getSFileName() )cc:Z7p  
{ :4|W;Lkd!  
return sFileName; gD0O7KO  
} d)m +Hc.  
.{as"h-.O  
4}B9y3W:v  
public void setSFileName(String value) 7_>No*[  
{ (JS1}T  
sFileName = value; X)iQ){21V  
} mx  s=<  
|eIEqq.Eb  
9W$FX  
public int getNSplitter() \`?l6'!  
{ a5o&6_  
return nSplitter; 0ts] iQ7  
} R[>fT}Lo  
`mV&[`NZ  
i,>yIPBU!  
public void setNSplitter(int nCount) (C/2shr 8  
{ ON~jt[  
nSplitter = nCount; 9J% ~?k  
} @ ]u nqCO  
} c%Y%c2([  
M{$EJS\d=  
qX[a\HQa  
/* >x0"gh  
**Utility.java 1au1DvH  
*/ "\bbe@  
package NetFox; I, 9!["^|  
@O b$w1c  
_W]qV2j  
public class Utility { L 1=HD  
E/9h"zowS  
,a&N1G.  
public Utility() zg,?aAm  
{ Rk8>Ak(/  
a[iuE`  
ur^)bp<n  
} SBo>\<@  
-d? 9Acd  
//线程睡眠 3uO#/EbS  
public static void sleep(int nSecond) `MFw2nu@t  
{ :JW!$?s8H  
try{ xj~ /C5@  
Thread.sleep(nSecond); GEU:xn  
} .-t#wXEi  
catch(Exception e) \"BoTi'2!  
{ Vrl)[st!;I  
e.printStackTrace (); ;pu68N(B  
} rnWU[U8%  
} :X-Z|Pv8  
mB &nN+MV  
//日志 $@kGbf~k  
public static void log(String sMsg) +9db1:  
{ FWqnlK#  
System.err.println(sMsg); 7g1" s1~or  
} M^I*;{w6i  
J+IQvOn_|  
46c7f*1l  
public static void log(int sMsg) ,@"Z!?e  
{ =qH9<,p`H  
System.err.println(sMsg); |5|^[v   
} L|4kv  
} !HyPe"`oL  
6@kKr  
y\L$8BSL  
/* Nx>WOb98  
**TestMethod.java >&V?1!N"  
*/ 5`CPaJT$  
package NetFox; yNVuSj  
:|/bEP]p/  
Rh#0EbE2  
public class TestMethod { AA&398F  
wW s<{ T  
Zp~2WJQ  
public TestMethod() Erz{{kf]1V  
{ ///xx/weblogic60b2_win.exe {B$cd?}  
try{ gAt[kW< n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /MHqt=jP6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); csZIBi  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Qzy[  
fileFetch.start(); {H OvJ`tM  
} yyZ}qnbx]  
catch(Exception e){e.printStackTrace ();} Bs2.$~   
oK1"8k|Z  
yGl (QLk  
} b5u_x_us|  
\q#s/&b   
z-(@j;.  
public static void main(String[] args) GFd~..$  
{ -AwR$<q'  
new TestMethod(); @ @$=MSN  
} |0nbO2}  
} .])ubK_9  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八