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
  • 8912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
/* )\7Cp-E-W  
**SiteFileFetch.java ,c 0]r;u!  
*/ #V$sb1u  
package NetFox; HZjuL.Tj  
import java.io.*; `R!2N4|;  
import java.net.*; t^}"8  
y|NY,{:]  
_Fe=:q  
public class SiteFileFetch extends Thread { Qz"//=hC|H  
0#ON}l)>  
1bHQB$%z  
SiteInfoBean siteInfoBean = null; //文件信息Bean {:KPEN  
long[] nStartPos; //开始位置 t gHN\@yj  
long[] nEndPos; //结束位置 $ e.Bz `  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 a54S,}|  
long nFileLength; //文件长度 {bG.X?b  
boolean bFirst = true; //是否第一次取文件 xk3)#*  
boolean bStop = false; //停止标志 "ZA`Lp;%w  
File tmpFile; //文件下载的临时信息 _ q AT%.  
DataOutputStream output; //输出到文件的输出流 *}_i[6_\E  
19RbIG/X  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b@sq}8YD|z  
public SiteFileFetch(SiteInfoBean bean) throws IOException \Ym!5,^o  
{ .4[M-@4+]  
siteInfoBean = bean; ylDfr){  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); = )4bf"~8  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8#9OSupp  
if(tmpFile.exists ()) "{3MXAFe  
{ ;Wsl 'e/  
bFirst = false; JvaHH!>d/  
read_nPos(); ]mjKF\  
} +;Gvp=hk  
else e@& 2q{Gi=  
{ QUg<~q)Oq  
nStartPos = new long[bean.getNSplitter()]; Hl*#iUq  
nEndPos = new long[bean.getNSplitter()]; lTFo#p_(  
} ABL5T-*]  
7M_GGjP  
F!2VTPm9z  
YG)7+94  
} |!1iLWQ  
\`%#SmQF  
(a~V<v"  
public void run() Yp8XZ 3  
{ V8b^{}nxt  
//获得文件长度 1^[]#N-Bu  
//分割文件 NxB/U_j  
//实例FileSplitterFetch ;=@?( n  
//启动FileSplitterFetch线程 ?%/*F<UVQ  
//等待子线程返回 4{b/Nv:b  
try{ v+dT7* ^@  
if(bFirst) l1%*LyD  
{ ZmI#-[/  
nFileLength = getFileSize(); QkLcs6)R  
if(nFileLength == -1) T b*Q4:r"  
{ $-6[9d-N  
System.err.println("File Length is not known!"); \lyHQ-gWhc  
} <l>L8{-3  
else if(nFileLength == -2) mXM U  
{ 3wfJ!z-E8  
System.err.println("File is not access!"); U.<ad  
} c:s[vghH^#  
else r4iT 9 D  
{ &yqk96z  
for(int i=0;i<nStartPos.length;i++) z^y -A ?  
{ 6'e 'UD  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); O<XNI(@  
} 6+C]rEY/o  
for(int i=0;i<nEndPos.length-1;i++) >R.!Qze\G  
{ ): r'IR  
nEndPos = nStartPos[i+1]; h*sL' fJ]  
} n:Dr< q .  
nEndPos[nEndPos.length-1] = nFileLength; 6^FUuj.  
} Lo" s12fr  
} =H^~"16  
(: mF+%(  
t1G2A`  
//启动子线程 j tqU`|FSQ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1J&hm[3[K  
for(int i=0;i<nStartPos.length;i++) Hq,N OP  
{ nQn=zbZ3  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gV'=u z v  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7'@~TM  
nStartPos,nEndPos,i); wB<cW>6  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tcI Z 2H%  
fileSplitterFetch.start(); t~Ic{%bdA  
} ZKi?;ta=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I#W J";kqB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VY0-18 o  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -or)NE  
nEndPos = " + nFileLength); T'N/A9{q  
// fileSplitterFetch[nPos.length-1].start(); gpCWXz')i  
g=Nde2d?  
;3Q3!+%j  
//等待子线程结束 lnV!Xuf  
//int count = 0; cQ0+kX<  
//是否结束while循环 Tcq@Q$H  
boolean breakWhile = false; PW9tZx#  
lW]&a"1$  
%B| Ca&  
while(!bStop) <S0gIg`)  
{ 'jKCAU5/0;  
write_nPos(); |;YDRI  
Utility.sleep(500); +V#dJ[,8;.  
breakWhile = true; / 6DW+!  
1#2L9Bi  
1\5po^Oioy  
for(int i=0;i<nStartPos.length;i++) ,LL=b-Es  
{ xJFxrG'c  
if(!fileSplitterFetch.bDownOver) Nxm '* -A  
{ h6D1uM"o   
breakWhile = false; X C '|  
break; <h`}I3Ao  
} =z}M(<G  
} Ul:M=8nE%  
if(breakWhile) &VVvZ@X;  
break; [kI[qByf  
quFNPdP  
q]y{ 4"=5  
//count++; SqoO"(1x  
//if(count>4) eW[](lGWM  
// siteStop(); 0'R}'  
} AQ,%5MeqJ  
; VQ:\f G  
L0ZAF2O  
System.err.println("文件下载结束!"); ) =|8%IrB  
} ` )~CT  
catch(Exception e){e.printStackTrace ();} kO,vHg$  
} <ol? 9tm  
+^%0/0e  
XZ|\|(6Cc  
//获得文件长度 {.r9l  
public long getFileSize() H8!lSRq  
{ H7Pw>Ta ;  
int nFileLength = -1; Wk]E6yz6  
try{ j8ac8J,}c  
URL url = new URL(siteInfoBean.getSSiteURL()); uecjR8\e  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CbT ;#0  
httpConnection.setRequestProperty("User-Agent","NetFox"); wd Di5-A4  
2c5)pIVEy  
8ZDWaq8^2N  
int responseCode=httpConnection.getResponseCode(); !:1BuiL  
if(responseCode>=400) |PLWF[+t8  
{ "T6s;'k  
processErrorCode(responseCode); ^i17MvT'  
return -2; //-2 represent access is error #LG<o3An  
} N\x<'P4q  
H(Ad"1~.#  
_(KzjOMt  
String sHeader; {)- 3g~  
q}J Eesf  
Vc "+|^  
for(int i=1;;i++) -4S4I  
{ g"D:zK)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  37|EG  
//Utility.log(in.readLine()); :tLMh08h  
sHeader=httpConnection.getHeaderFieldKey(i); e`% <D[-  
if(sHeader!=null) }9L;|ul6  
{ jft@ 'W53  
if(sHeader.equals("Content-Length")) h ?+vH{}j  
{ BNbz{tbX"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2O0</^Z%E  
break; E1|:t$>Ld  
} r5uX?^mJ0  
} Q_|Lv&  
else .vpx@_;]9  
break; .WW|v  
} iMp_1EXe  
} !A"-9OS2  
catch(IOException e){e.printStackTrace ();} ^L's45&_  
catch(Exception e){e.printStackTrace ();} !GZ{UmwA  
'zYx4&s  
CSMx]jbb  
Utility.log(nFileLength); [3(lk_t  
f`p"uLNo<  
N1'$;9 c  
return nFileLength; '6Yx03t  
} iKgH :[j  
E^V4O l<  
:z+l=d:4  
//保存下载信息(文件指针位置) f >\~h,SLL  
private void write_nPos() oo!JAv}~  
{ !Bb^M3iA  
try{ ngH_p>  
output = new DataOutputStream(new FileOutputStream(tmpFile)); S{qsq\X  
output.writeInt(nStartPos.length); r1|;V~ a$~  
for(int i=0;i<nStartPos.length;i++) 6 kAXE\T  
{ s!/Q>A  
// output.writeLong(nPos); fMRMQR=6B  
output.writeLong(fileSplitterFetch.nStartPos); UjS,<>fm  
output.writeLong(fileSplitterFetch.nEndPos); /@K1"/fqH  
} lhJZPnx~  
output.close(); &y:SK)  
} /??nO Vvt  
catch(IOException e){e.printStackTrace ();} +rOd0?  
catch(Exception e){e.printStackTrace ();} <0H^2ekd  
} b'G!)n  
=' #yG(h  
etH]-S  
//读取保存的下载信息(文件指针位置) |&rxDf}W  
private void read_nPos() (/Dr=D{ `  
{ |(rTz!!-  
try{ -{S: sK.o  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y kcN-  
int nCount = input.readInt(); O.OSLezTQ  
nStartPos = new long[nCount]; &e1(|qax  
nEndPos = new long[nCount]; Z=>#|pW,)  
for(int i=0;i<nStartPos.length;i++) [xg& `x9,.  
{ .V|o-~c  
nStartPos = input.readLong(); J, vEZT<Mt  
nEndPos = input.readLong(); 6?KJ"Ai9  
} EnXTL]=0S  
input.close(); X##hSGQM  
} BW&)Zz  
catch(IOException e){e.printStackTrace ();} _.3O(?p,  
catch(Exception e){e.printStackTrace ();} #Ue_  
} ]jwF[D  
.06[*S  
w:o,mzuXK  
private void processErrorCode(int nErrorCode) kY`L[1G$  
{ _0qp!-l}  
System.err.println("Error Code : " + nErrorCode); DsF<P@O6  
} _tpqo>  
Y'2 |GJc2  
;TG<$4N  
//停止文件下载 yX|0 R H  
public void siteStop() +(J{~A~  
{ SHP_  
bStop = true; ($Ck5`_MK  
for(int i=0;i<nStartPos.length;i++) y4 ~;H{!  
fileSplitterFetch.splitterStop(); wdTjJf r  
Ce_E S.  
$${9 %qPzb  
} D$G:#z*  
} R(N5K4J  
//负责部分文件的抓取 X2hyxTOp  
**FileSplitterFetch.java fkK42*U@r  
*/ \Dr?}D  
package NetFox; P+[\9Gg  
8iwqy0<  
tJ!s/|u(  
import java.io.*; NU$?BiB?R  
import java.net.*; UqaV9  
8!u8ZvbFG  
 a 9f%p  
public class FileSplitterFetch extends Thread { }o MY  
y(0";\V  
IJV1=/ NJW  
String sURL; //File URL pcjb;&<  
long nStartPos; //File Snippet Start Position 5t~p99#?  
long nEndPos; //File Snippet End Position [DO UIR9  
int nThreadID; //Thread's ID E]j2%}6Z%  
boolean bDownOver = false; //Downing is over \dw*yZ^  
boolean bStop = false; //Stop identical zeG_H}[2&  
FileAccessI fileAccessI = null; //File Access interface D "9Hv3  
gl~>MasV&  
mu}T,+9\  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t^-yK;`?q:  
{ JVeb$_0k  
this.sURL = sURL; Ju.B!)uS#  
this.nStartPos = nStart; {P@OV1  
this.nEndPos = nEnd; COk;z.Kn  
nThreadID = id; yCT:U&8%F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6`Af2Y_  
} eW^_YG%(  
4` zfrT^  
O+Qt8,  
public void run() *%wfR7G[B  
{ j=~c( B  
while(nStartPos < nEndPos && !bStop) l2LUcI$ x  
{ aL%amL6CX  
?A7_&=J%  
dwAFJhgh  
try{ N++jI(  
URL url = new URL(sURL); P(#by{s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7Ta",S@m  
httpConnection.setRequestProperty("User-Agent","NetFox"); m?Qr)F_M  
String sProperty = "bytes="+nStartPos+"-"; 3>t^Xu~  
httpConnection.setRequestProperty("RANGE",sProperty); ME%W,B.|"s  
Utility.log(sProperty); ;.4A,7w#  
(( D*kd"  
o:irwfArv  
InputStream input = httpConnection.getInputStream(); ,3tcti~sZ  
//logResponseHead(httpConnection); pk0C x  
V)8d1S  
7$&3(#!N  
byte[] b = new byte[1024]; }^ np  
int nRead; o<r|YRzQl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kxp, ZP  
{ g1s\6%g  
nStartPos += fileAccessI.write(b,0,nRead); b;XUv4~V  
//if(nThreadID == 1) *.]M1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UfUboxT  
} Zw`vPvb!  
;>d uY\$<  
!$i*u-%4  
Utility.log("Thread " + nThreadID + " is over!"); <p74U( V  
bDownOver = true; !K~:crUV|S  
//nPos = fileAccessI.write (b,0,nRead); tuF hPqe {  
} lSzLR~=Au  
catch(Exception e){e.printStackTrace ();} `Z:5E  
} <cn{S`  
} v9qgfdBS5  
@GpM 4>:  
dE[nPtstb  
//打印回应的头信息 &eHhj9  
public void logResponseHead(HttpURLConnection con) |_^A$Hv  
{ I*Q^$YnM  
for(int i=1;;i++) N5%zbfKM  
{ 9j;L-  
String header=con.getHeaderFieldKey(i); "X }@VT=  
if(header!=null) SXW8p>1Jw  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }(/")i4h  
Utility.log(header+" : "+con.getHeaderField(header)); " tUS>c/  
else )d\u_m W^  
break; q{?ku!cL  
} V{j>09u  
} ?!:$Z4G  
cJnAwIs_e`  
}  :@s  
public void splitterStop() >K2Md*[P3q  
{ (\UA+3$4  
bStop = true; YGj3W.eH  
} Rt[zZv  
t'@qb~sf  
!u0qF!/W  
} lo%:$2*'p  
nK" XyZ&  
;%j1'VI  
/* pS3TD"p  
**FileAccess.java ;gC.fpu  
*//文件访问(定位,写) #=G[ ~m\  
package NetFox;  .UUY9@  
import java.io.*; "AzA|zk')"  
0?tn.<'B8T  
%$)[qa3  
public class FileAccessI implements Serializable{ FM)Es&p&  
YtzB/q8I  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pt rQ~m-  
RandomAccessFile oSavedFile; 5jTBPct   
long nPos; Aqwjs 3  
B4yC"55  
*[-% .=[7  
public FileAccessI() throws IOException e*7nq ~ B5  
{ wIv_Z^% V  
this("",0); Tq r]5  
} )Bl0 W  
b0A*zQA_)  
UKBVCAK  
public FileAccessI(String sName,long nPos) throws IOException }w0>mA0=H  
{ xMAfa>]{n  
oSavedFile = new RandomAccessFile(sName,"rw"); Iq@:n_~  
this.nPos = nPos; q\P"AlpC!  
oSavedFile.seek(nPos); LG0z|x(  
} fI5]ed eS  
]ZQ3|ZJ?<  
"QWF&-kAI  
public synchronized int write(byte[] b,int nStart,int nLen) =,/08Cs  
{ :3z`+5Y*  
int n = -1; ~JJuM  
try{ GvL)SVv?  
oSavedFile.write(b,nStart,nLen); E,F'k2yU  
n = nLen; 1 h.=c  
} \a|Fh hI  
catch(IOException e) P,2FH2Eyj  
{ Hqel1J  
e.printStackTrace (); ;^q@w  
} j{i3lGaN  
7gLN7_2  
: "|M  
return n; V'XmMn)!  
} T+OQa+E@P  
\,-t]$9  
e;y\v/A  
} k* ayzg3F>  
lzQmD/i*  
. C g2Y  
/* I.[2-~yf  
**SiteInfoBean.java QBg~b{h  
*/ YceX)  
package NetFox; y~.k-b<{[  
p7UdZOi2  
bZ-"R 6a$  
public class SiteInfoBean { Op&i6V}<s  
xQ[~ c1  
b h%@Lo  
private String sSiteURL; //Site's URL 7~2b4"&  
private String sFilePath; //Saved File's Path (vq0Gl  
private String sFileName; //Saved File's Name i?.7o*w8  
private int nSplitter; //Count of Splited Downloading File I Xm}WTgF!  
wUGSM"~ |  
mgIB8D+6  
public SiteInfoBean() 7QXA*.' F  
{//nSplitter的缺省值为5 rOt`5_2f  
//default value of nSplitter is 5 C%$:Oq  
this("","","",5); 7oPLO(0L  
} Y#>'.$ (Az  
C@{#OOa  
|i)7j G<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h L 1q9%  
{ cs]N%M^s  
sSiteURL= sURL; O F$0]V  
sFilePath = sPath; [Yo3=(7J  
sFileName = sName; 'W!N1W@  
this.nSplitter = nSpiltter; 8oM]gW;J~  
?-40bb  
|\yVnk!c  
} 1o&] =(  
IFrq\H0  
%\5 wHT+)  
public String getSSiteURL() 3#{{+5G  
{ 83 O+`f  
return sSiteURL; gnW]5#c@  
} c-|~ABtEpX  
8VbHZ9Q  
fOE8{O^W  
public void setSSiteURL(String value) X2X.&^  
{ 5H (CP  
sSiteURL = value; dKs^Dq  
} J^}w,r *=  
o5!"dxR  
Q_ zGs6  
public String getSFilePath() *h+@a  
{ {`2R<O  
return sFilePath; Y<~N x~w{  
} X6+2~'*t  
(AHZmi V  
\E9Hk{V:6  
public void setSFilePath(String value) + 9vd(c  
{ c6IFt4)g  
sFilePath = value; h5+qP"n!?q  
} K"p$ga{  
>Oary  
c,cc avv{I  
public String getSFileName() }( x|  
{ ']nB_x7  
return sFileName; u"rK5'  
}  tCT-cs  
-P|EV|8=  
oV4+w_rrLc  
public void setSFileName(String value) S >E|A %  
{ 1b4aY> Z  
sFileName = value; "`b"PQ<x  
} ,XD'f  
@,Je*5$o"  
#41fRmzC  
public int getNSplitter() kOv2E]  
{ [;bZQ6JR  
return nSplitter; TTg>g~t`  
} @]*b$6tt  
v&BKl  
gv&%2e}_  
public void setNSplitter(int nCount) nZ;h&N -_-  
{ pEUbP,3M:  
nSplitter = nCount; ]<9=%m  
} VieX 5  
} O>zPWVwa  
I y?_2m  
y[U/5! `zV  
/* x/nlIoT  
**Utility.java U) tqo_  
*/ g+5{&YD  
package NetFox; 4@,d{qp~  
Y{].%xM5  
{`Ekv/XWa  
public class Utility { yY,O=yOjq  
("2ukHc  
H*#L~!]  
public Utility() @"M%ZnFu  
{ :HSqa9>wa  
~vD7BO`  
sE*A,z?  
} EN lqoj1  
T*,kBJ  
//线程睡眠 V^ O dTM  
public static void sleep(int nSecond) j, SOL9yg  
{ (kpn"]^'  
try{ zYf `o0U  
Thread.sleep(nSecond); .&:GO D  
} GA19=gow  
catch(Exception e) bM]\mo>z<  
{ @(XX68  
e.printStackTrace ();  &Gp~)%  
} x+j5vzhG)  
} W"9?D  
!V~`e9[rl  
//日志 al/3$0#U  
public static void log(String sMsg) {}Y QB'}  
{ SHw%u~[hu  
System.err.println(sMsg); sb 3l4(8g  
} fo63H'7  
y'(bp=Nq  
tw. 2h'D  
public static void log(int sMsg) >QwZt  
{ pfj%AP:  
System.err.println(sMsg); d*%-r2K  
} yZf+*j/a7  
} (<ybst6+I  
?b',kN,(  
az7<@vSXi  
/* 9Y:JA]U&8  
**TestMethod.java 65FdA-4  
*/ iz'#K?PF_  
package NetFox; }D5*   
qaBjV6loy  
&KfRZ`9H  
public class TestMethod { #J AU5d  
(bfHxkR.  
D#>+]}5@x  
public TestMethod() pdnkHR$  
{ ///xx/weblogic60b2_win.exe Xg*IOhF6x  
try{ lk $S"OH!  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &FrW(>2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]?P9M<0PM  
SiteFileFetch fileFetch = new SiteFileFetch(bean); x)6yWr[ri%  
fileFetch.start(); te ?R(&  
} @kR/=EfS  
catch(Exception e){e.printStackTrace ();} V1R=`  
. e2qa  
Hu$]V*rAG  
} >S /Zd  
&*TwEN^h  
du2q6"  
public static void main(String[] args) iqecm]Z0  
{ (5@9j  
new TestMethod(); 8+Lig  
} 5TlPs_o  
} '>:mEXK}w  
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:
10+5=?,请输入中文答案:十五