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
  • 9388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
/* C6JwJYa  
**SiteFileFetch.java mI,a2wqi  
*/ $RA+StF!]  
package NetFox; SpO%nZ";g8  
import java.io.*; u?4d<%5R!  
import java.net.*; @?n~v^  
r1&eA%eh  
{i<L<Y(3  
public class SiteFileFetch extends Thread { |4C5;"Pc  
<YM!K8hu$  
P<CPA7K  
SiteInfoBean siteInfoBean = null; //文件信息Bean 2RU/oqmR  
long[] nStartPos; //开始位置 ~v@.YJoZ4Z  
long[] nEndPos; //结束位置 wzj :PS  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :u,Ji9 u  
long nFileLength; //文件长度 h1~/zM/`  
boolean bFirst = true; //是否第一次取文件 7](aPm8  
boolean bStop = false; //停止标志 :IX_|8e ^  
File tmpFile; //文件下载的临时信息 ^\oMsU5(  
DataOutputStream output; //输出到文件的输出流 r0Zj'F_e  
C14"lB.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 3o2x&v  
public SiteFileFetch(SiteInfoBean bean) throws IOException kmg/hNtN  
{ \IhHbcF`d  
siteInfoBean = bean; ;uho.)%N`F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); wii.0~p  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); :-Wh'H(  
if(tmpFile.exists ()) HPY;U N  
{ gXj3=N(l  
bFirst = false; j.yh>"de  
read_nPos(); 84lT# ^q  
} &s{d r  
else I.gF38Mx  
{ Ub{7Xk n  
nStartPos = new long[bean.getNSplitter()]; Y1;jRIOA  
nEndPos = new long[bean.getNSplitter()]; {(IHHA>  
} D4T42L  
mhMTn*9  
q:1n=i Ei  
uO((Mg  
} $3S`A]xO  
{Ia1Wd8n  
Gb4p "3  
public void run() J'%W_?wZ  
{ ,z01 *Yx  
//获得文件长度 x21XzGLY|}  
//分割文件 t>2EZ{N +y  
//实例FileSplitterFetch mT>RQ.  
//启动FileSplitterFetch线程 -;O"Y?ME  
//等待子线程返回 Byh!Snoe  
try{ dG!)<  
if(bFirst) dbg%n 0h  
{ .:t&LC][  
nFileLength = getFileSize(); _Qq lOc9  
if(nFileLength == -1) v\g1 w&PN  
{ u"F{cA!B  
System.err.println("File Length is not known!"); w0O(>  
} k/M{2Po+  
else if(nFileLength == -2) !TN)6e7`  
{ H~?7 : K  
System.err.println("File is not access!"); BxiR0snf0q  
} KP`Pzx   
else WQ9VcCY  
{ h %5keiA  
for(int i=0;i<nStartPos.length;i++) 5S ) N&%  
{ XaaR>HljJ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Rw<O%i5/d  
} .7+"KP:  
for(int i=0;i<nEndPos.length-1;i++) ~wu\j][2  
{ !Ld[`d.|R!  
nEndPos = nStartPos[i+1]; },;Z<(  
} [M#(su0fv  
nEndPos[nEndPos.length-1] = nFileLength; )=!|^M  
} y,6KU$G  
} >x]ir  
~"Su2{"8B  
L/)eNZ  
//启动子线程 N+vsQ!Qz  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z2jS(N?J1  
for(int i=0;i<nStartPos.length;i++) sT,*<^  
{ od^o9(.W^  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iM$iZ;Tp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k&:~l@?O  
nStartPos,nEndPos,i); @W=: r/  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I5]58Ohx  
fileSplitterFetch.start(); Qnx?5R-}ZU  
} }+giQw4  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;<=z^1X9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1I%niQv5t  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L+lX$k  
nEndPos = " + nFileLength); HP=5 a.  
// fileSplitterFetch[nPos.length-1].start(); YXg^t$  
)"g @"LJ=  
?z3|^oU~d  
//等待子线程结束 U^Iq]L  
//int count = 0; t1p[!53(  
//是否结束while循环 CQA^"Ll  
boolean breakWhile = false; Hn]6re  
ItE)h[86  
D77$aCt  
while(!bStop) P )[QC  
{ ^vZu[ m  
write_nPos(); (hIe!"s *  
Utility.sleep(500); aN';_tGvK  
breakWhile = true; lr[&*v?h  
gu1n0N`b  
(\4YBaGd  
for(int i=0;i<nStartPos.length;i++) \*#E4`Y  
{ &-KQ m20n  
if(!fileSplitterFetch.bDownOver) `a8&7 J(  
{ 9 1ec^g  
breakWhile = false; y(j vl|z[  
break; ,w,)n^  
} +$R%Vbd  
} }7i}dyQv}  
if(breakWhile) JY9hD;`6y  
break; d3p;[;`  
D7C%Y^K]>E  
zc1~ q  
//count++; f.RwV+lq  
//if(count>4) 787}s`,}  
// siteStop(); { /Gm|*e{  
}  W|6.gN]  
GFZx[*+%%z  
bQwiJ`B&  
System.err.println("文件下载结束!"); RohD.`D  
} 7mYBxE/  
catch(Exception e){e.printStackTrace ();} ROj=XM:+  
} J!:v`gb#@A  
h)T-7b  
F5<GGEQb  
//获得文件长度 _p| KaT``  
public long getFileSize() gWy2E;"a  
{ [jF\"#A  
int nFileLength = -1; :#p!&Fi  
try{ 4kQL\Ld#E%  
URL url = new URL(siteInfoBean.getSSiteURL()); '^.}5be&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %Tv^BYQAZ  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^k}jPc6  
@y`7csb p  
<ba+7CK] w  
int responseCode=httpConnection.getResponseCode(); -* ;`~5  
if(responseCode>=400) qbe9 CF'@_  
{ YNi3oG]h  
processErrorCode(responseCode); nLjo3yvV..  
return -2; //-2 represent access is error tvG/oe .1'  
} e#$ZOK)`  
ocT.2/~d  
1~#p3)B  
String sHeader; }nJG<rY  
oXkxd3  
hkL[hD  
for(int i=1;;i++) yjP;o`z%  
{ vMOit,{  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f i3<  
//Utility.log(in.readLine()); Zj8aD-1]U^  
sHeader=httpConnection.getHeaderFieldKey(i); eqze7EY  
if(sHeader!=null) yegTKoY  
{ <ctn_"p Z  
if(sHeader.equals("Content-Length")) KD7 RI3'?  
{ Y+tXWN"8  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W@x UR-}51  
break; O5Xu(q5+  
} |0mVK`  
} }GCt)i_  
else f9g#pyH4  
break; 0VB~4NNR  
} /*bS~7f1  
}  98os4}r  
catch(IOException e){e.printStackTrace ();} "oYyeT ,?  
catch(Exception e){e.printStackTrace ();} lc=C  
\S@;>A<J  
<"@~  
Utility.log(nFileLength); :sBg+MS  
& ;+u.X  
o~F @1  
return nFileLength; @l^=&53T  
} Fr)G h>  
|.Bb Pfe8f  
#"a?3!wr  
//保存下载信息(文件指针位置) $@t-Oor;  
private void write_nPos() M? oK@i  
{ /}Y>_8 7  
try{ >yn%.Uoh@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); /GNRu  
output.writeInt(nStartPos.length); -tSWYp{  
for(int i=0;i<nStartPos.length;i++) pAYH"Q6~)I  
{ +n]U3b  
// output.writeLong(nPos); *lg1iP{]  
output.writeLong(fileSplitterFetch.nStartPos); jBV2]..  
output.writeLong(fileSplitterFetch.nEndPos); =/" Of  
} lkV% k1w  
output.close(); dfe 9)m>  
} &eT)c<yhyK  
catch(IOException e){e.printStackTrace ();} x{C=rdp__  
catch(Exception e){e.printStackTrace ();} 4em7PmT  
} sf]y\_zU  
/!UuGm   
+}X?+Epm  
//读取保存的下载信息(文件指针位置) )]!Ps` ,u  
private void read_nPos() 2s;/*<WM  
{ fEdQR->  
try{ VY@uQ#&A  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @?{n`K7{`  
int nCount = input.readInt(); ,-t3gc1~X  
nStartPos = new long[nCount]; 4-=>># P  
nEndPos = new long[nCount]; fSl+;|K n  
for(int i=0;i<nStartPos.length;i++) \i "I1xU  
{ 7C ABM  
nStartPos = input.readLong(); Nc[>CgX"@  
nEndPos = input.readLong(); cg<10KT  
} $ # @G!  
input.close(); (80]xLEBL  
} R,/?p  
catch(IOException e){e.printStackTrace ();} )dG7 $,g  
catch(Exception e){e.printStackTrace ();} \^?BC;s^C  
} PX[taDN  
Rs{L  
B>t$Z5Q^X  
private void processErrorCode(int nErrorCode) 9C$b^wHd  
{ y)|Q~8r  
System.err.println("Error Code : " + nErrorCode); 6t TLyI$+  
} HLAWx/c,j"  
F^IYx~:  
Z~~{!C+G  
//停止文件下载 [sTr#9Z  
public void siteStop() De4UGX  
{ mmAikT#k  
bStop = true; LSNa  
for(int i=0;i<nStartPos.length;i++) z* YkD"]B  
fileSplitterFetch.splitterStop(); kG &.|  
 ^P~%^?(  
$=4T# W=m  
} d%81}4f:  
} ?2%d;tW  
//负责部分文件的抓取 bAeC=?U  
**FileSplitterFetch.java +e`f|OQ  
*/ Iujly f  
package NetFox; 2+TCFpv  
05LVfgJ'q  
_jR%o1Y}  
import java.io.*; 5.]+K<:h"A  
import java.net.*; rm;'/l8Y-E  
Ps+0qqT*  
GX&BUP\  
public class FileSplitterFetch extends Thread { \s<{V7tq  
m(s(2wq"f  
~urIA/  
String sURL; //File URL wXMKQ)$(  
long nStartPos; //File Snippet Start Position BdG~y1%:  
long nEndPos; //File Snippet End Position (#BkL:dg  
int nThreadID; //Thread's ID ,fpu@@2  
boolean bDownOver = false; //Downing is over *$Z}v&-0k  
boolean bStop = false; //Stop identical lt|\$Iy(  
FileAccessI fileAccessI = null; //File Access interface Sf B+;i'D  
^rfY9qMJr8  
w0)V3  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^&zwO7cS  
{ C~ t?<  
this.sURL = sURL; ]iRE^o6  
this.nStartPos = nStart; wOOBW0tj  
this.nEndPos = nEnd; yMq&9R9F  
nThreadID = id; (8TB*BhQ_  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >N@tInE  
} =<e|<EwSZ  
`utv@9 _z  
jGl8y!aM  
public void run() n.ZLR=P4  
{ 0^az<!!O#  
while(nStartPos < nEndPos && !bStop) uz-,)  
{ iZ<^p1i  
9 [v=`  
Bw;sg;  
try{ n1m[7s.[&  
URL url = new URL(sURL); dF:@BEo  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4 sasf94  
httpConnection.setRequestProperty("User-Agent","NetFox"); k{;"Aj:iL  
String sProperty = "bytes="+nStartPos+"-"; 0?KXQD  
httpConnection.setRequestProperty("RANGE",sProperty); N+ZDQa[  
Utility.log(sProperty); <cNXe4(  
X1&Ug ^  
3sIW4Cs7)U  
InputStream input = httpConnection.getInputStream(); ig<Eyr  
//logResponseHead(httpConnection); 1j0OV9-|  
4e~^G  
l9KL P  
byte[] b = new byte[1024]; "RMBV}<T  
int nRead; W^npzgDCo  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5b45u 6  
{ 4 YDK`:4I~  
nStartPos += fileAccessI.write(b,0,nRead); Ko_Sx.  
//if(nThreadID == 1) C~4_Vc*  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yv k Qh{  
} BLZ#vJR  
PLU8:H@X  
=+5z;3  
Utility.log("Thread " + nThreadID + " is over!"); JTK>[|c9oE  
bDownOver = true; !>fYD8Ft,  
//nPos = fileAccessI.write (b,0,nRead); 9qN4f8R  
} J!5BH2bg  
catch(Exception e){e.printStackTrace ();} x2x) y08  
} cKuU#&FaV  
} B?A c  
1{+x >Pv:  
b ?9c\-}  
//打印回应的头信息 arJ4^  d  
public void logResponseHead(HttpURLConnection con) :W]?6=  
{ ^7M hnA  
for(int i=1;;i++) Y$xO&\&)  
{ V ij P;  
String header=con.getHeaderFieldKey(i); [M>Md-pj  
if(header!=null) 0q'd }DW  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j_N><_Jc  
Utility.log(header+" : "+con.getHeaderField(header)); <X[TjP  
else h4rIt3`  
break; U |I>CDp  
} +Go(y S  
} [-o`^;  
1Vq]4_09g1  
qu]ch&"?U  
public void splitterStop() I)#=#eI* :  
{ 0#(K}9T)  
bStop = true; m|q?gX9R  
} [Du@go1C  
1d/-SxhZ  
0dS}p d">k  
} VBc[(8o  
l`lo5:w  
+pYrAqmO-  
/* fw>@:m_bK  
**FileAccess.java *r!f! eA:  
*//文件访问(定位,写) >! +.M9  
package NetFox; u\YH,  
import java.io.*; 0kN;SSX!  
8N<0|u  
z;1y7W!v  
public class FileAccessI implements Serializable{ |8I #`  
@$FE}j_  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d,=Kv  
RandomAccessFile oSavedFile;  >)ZX  
long nPos; gfQ&U@N  
\)'nxFKqV  
=! v.VF\;  
public FileAccessI() throws IOException WelB+P2  
{ 3/I Q]8g"  
this("",0); VM{`CJ2  
} `-zdjc d  
R"(rL5j  
* d6[k Y  
public FileAccessI(String sName,long nPos) throws IOException Hj ]$  
{ /x.TF'Z*  
oSavedFile = new RandomAccessFile(sName,"rw"); o?\)!_Z|  
this.nPos = nPos; }qfr&Ffh@  
oSavedFile.seek(nPos); A.7:.5Cx'  
} F\1nc"K/(  
:0o $qz2  
 j`^':!  
public synchronized int write(byte[] b,int nStart,int nLen) R`=3lY;  
{  ToNi<~  
int n = -1; >yvP[$]!6  
try{  {ZFa +  
oSavedFile.write(b,nStart,nLen); >Bp%~8f  
n = nLen; -oq!zi4:  
} JV'd!5P  
catch(IOException e) 5@c,iU-L  
{ ,2S <#p!  
e.printStackTrace (); BmYU#h  
}  k*|dX.C:  
oR}ir  
iHjo3_g)n  
return n; Hxr2Q]c?u  
} b3b 4'l   
~\dpD  
TRz~rW k  
} 1_:1cF{w  
mm$D1=h{|  
o^~6RZ  
/* c?) pn9  
**SiteInfoBean.java 1=#r$H  
*/ %Hv$PsSJ  
package NetFox; *pP"u::S  
DHpU?;|3  
a#H=dIj  
public class SiteInfoBean { V2es.I  
AX**q$ 'R  
`.a L>hf  
private String sSiteURL; //Site's URL .Q"3 [  
private String sFilePath; //Saved File's Path ;t%L (J  
private String sFileName; //Saved File's Name ,-  ]2s_  
private int nSplitter; //Count of Splited Downloading File Te'^O,C)y$  
=D5@PHpv(  
2`5(XpYe  
public SiteInfoBean() 4\pA^%73  
{//nSplitter的缺省值为5 dQM# -t4*  
//default value of nSplitter is 5 'G(N,vu[@  
this("","","",5); $ajw]2kx  
} e"r'z n  
3FPy"[[  
I#eIm3Y?  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yE9JMi 0  
{ i?=3RdP/R1  
sSiteURL= sURL; &4*&L.hPM^  
sFilePath = sPath; %>I!mD"X\  
sFileName = sName; vlIdi@V  
this.nSplitter = nSpiltter; qjR;c& qR  
p5F[( H|9  
>[|:cz  
} R5]R pW=G  
CyG@  
bDUGzezP<  
public String getSSiteURL() $L</{bXW  
{ YD@V2gK  
return sSiteURL; @1n0<V /  
} m.K"IXD  
{h9#JMIA  
q<c).4  
public void setSSiteURL(String value) Dj!J 4uD  
{ ] {NY;|&I'  
sSiteURL = value; :\80*[=;Z  
} pbqa  
$Z{ fKr  
&)s A(  
public String getSFilePath() AZl=w`;/O%  
{ $ya#-pi`;  
return sFilePath; D<xPx  
} I*lq0&  
uaU!V4-  
!]kn=7  
public void setSFilePath(String value) 5j ]}/Aq  
{ N# ,4BU  
sFilePath = value; Nm,v E7M  
} W;KHLHp-  
tAc;O[L  
$u3N ',&  
public String getSFileName() ; $y.+5 q  
{ 1Eg}qU,:  
return sFileName; o.Cj+`0}5  
} aaaC8;.  
5lU`o  
ie$=3nZJ}  
public void setSFileName(String value) 8|d[45*q  
{ ~(%G; fZ?x  
sFileName = value; QT|mN  
} K/%aoTO}  
,/d-o;W  
a#raUF7e  
public int getNSplitter() 'm2,7]  
{ MnX2sX|  
return nSplitter; 5mFi)0={y  
} jM7}LV1Ck  
x65e,'  
$~:hv7%  
public void setNSplitter(int nCount) 1%-?e``.  
{ hG ]jm  
nSplitter = nCount; nEGku]pCH{  
} &[Sw:{&*jv  
} Ko%rB+d  
\/$v@5  
{;-$;\D  
/* 3[e@mcO  
**Utility.java S((8DSt*  
*/ ar^`r!ABEh  
package NetFox; jWoo{+=D  
HFDg@@  
D^TKv;%d  
public class Utility { [2FXs52  
5o72X k  
sV*Q8b*  
public Utility() m# SZI}  
{ XG [%oL  
-[7.VP   
,2cw9?<  
} bZlAK)  
V2y[IeSQ  
//线程睡眠 P;y/`_jo  
public static void sleep(int nSecond) l%U9g  
{ 3n/L; T,X  
try{ ?3|ZS8y  
Thread.sleep(nSecond); es6e-y@e  
} FE5R ^W#u-  
catch(Exception e) O^<6`ku  
{ y~dW=zO  
e.printStackTrace (); Qz<-xe`o8]  
} 3dM6zOK  
} Wu}Co  
:#LB}=HQ  
//日志 >:xnjEsi$/  
public static void log(String sMsg) ~W#f,mf  
{ 7]^Cg;EtM:  
System.err.println(sMsg); Oh^X^*I$@  
} i3GvTg-X  
c]LH.  
tb i;X=5  
public static void log(int sMsg) P``hw=L  
{ a=J?[qrx  
System.err.println(sMsg); .dygp"*  
} {NFeX'5bP  
} ::R^ w"  
lt*k(JD  
9@j~1G%^  
/* l?~ci ;lG  
**TestMethod.java p"JSYF 9]  
*/ UtutdkaS  
package NetFox; V.4j?\#%  
MPB6  
a_ P[J8j  
public class TestMethod { -Z Z$ 1E  
?yz%r`;r  
(kHR$8GFM  
public TestMethod() bXW)n<y  
{ ///xx/weblogic60b2_win.exe q5 A+%#  
try{ e%P;Jj476  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H )}WWXK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zm:=d>D..  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !vB%Q$!x  
fileFetch.start(); R',w~1RV'  
} M;9+L&p=  
catch(Exception e){e.printStackTrace ();} 0 mQ3P.9  
@b/2'  
sHuz10  
} +wSm6*j7=  
 )L!R~F C  
KC u6:)6'  
public static void main(String[] args) ]~zJ7I  
{ s`J=:>9*  
new TestMethod(); :6/OU9f/R  
} B#MW`7c  
} rrWk&;?  
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:
10+5=?,请输入中文答案:十五