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
  • 7187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
/* p#@#$u-  
**SiteFileFetch.java aGD< #]  
*/ s<O$ Y  
package NetFox; ~aob@(  
import java.io.*; $YSXE :  
import java.net.*; jeC=s~  
#{cy(&cz  
@aIgif+v  
public class SiteFileFetch extends Thread { 5'zXCHt  
}Le]qR9Y]  
U$OZkHA[  
SiteInfoBean siteInfoBean = null; //文件信息Bean +,76|oMsQ%  
long[] nStartPos; //开始位置 `b?uQ\#-M  
long[] nEndPos; //结束位置 7UfNz60+~  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ZVjB$-do  
long nFileLength; //文件长度 ;*(-8R/  
boolean bFirst = true; //是否第一次取文件 7~7L5PRW  
boolean bStop = false; //停止标志 '~[8>Q>  
File tmpFile; //文件下载的临时信息 5J5?cs-!  
DataOutputStream output; //输出到文件的输出流 w#"\*SKK  
XNz+a|cF  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) "aJHCi~l  
public SiteFileFetch(SiteInfoBean bean) throws IOException +9_Y0<C  
{ &hOz(825r  
siteInfoBean = bean; EQ1**[$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]  ,|,/~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); zHJCXTM  
if(tmpFile.exists ()) =X$ieXq|  
{ ={BD*= i  
bFirst = false; jq+(2  
read_nPos(); um2a#6uo  
} p+d-7'?I  
else .biq)L e  
{ Kj4/fB  
nStartPos = new long[bean.getNSplitter()]; ? #K|l*  
nEndPos = new long[bean.getNSplitter()]; ]E`<8hRB  
} zggnDkC5  
J@3,  
g)X3:=['  
`Q@7,z=f  
} &uq.k{<p\  
&K^0PzWWof  
fLDrit4_Q  
public void run() |L2>|4  
{ m^A2 8X7  
//获得文件长度  384n1?  
//分割文件 DH(<{ #u  
//实例FileSplitterFetch FQZ*i\G>>  
//启动FileSplitterFetch线程 /3b *dsYsl  
//等待子线程返回 SDnl^a  
try{ S$mv(C  
if(bFirst) !=[Y yh  
{ q}{E![ZTu  
nFileLength = getFileSize(); 0Hnj<|HL  
if(nFileLength == -1) 8D*7{Q  
{ 1 .3#PdMR,  
System.err.println("File Length is not known!"); [M|^e;tWK  
} =*\s`ox`  
else if(nFileLength == -2) n Bu!2c  
{ ?@64gdlwq  
System.err.println("File is not access!"); OH`a3E{e  
} \6b~$\~B  
else `|t,Uc|7!  
{ k&Pt\- 9on  
for(int i=0;i<nStartPos.length;i++) S=@+qcI  
{  }k^uup*{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); .;? Bni  
} 1Bytu >2  
for(int i=0;i<nEndPos.length-1;i++) A  6(`  
{ x YS81  
nEndPos = nStartPos[i+1]; ~A0]vcP  
} {[y6qQm  
nEndPos[nEndPos.length-1] = nFileLength; $WA wMS,  
} IiYL2JS;t|  
} mF7 Ak&So^  
G~9m,l+  
sx,$W3zI'G  
//启动子线程 FYAEM!dyy  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Sn=6[RQ>P  
for(int i=0;i<nStartPos.length;i++) 3smkY  
{ \:vF FK4a  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WogUILB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ot=>~(u0  
nStartPos,nEndPos,i); .3 EZk86  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,KY;NbL-Jp  
fileSplitterFetch.start(); k8gH#ENNK  
} E|O&bUMh  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), At7!Pas#@g  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]N>ZOV,>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #:)'D?,  
nEndPos = " + nFileLength); sI>w#1.m/&  
// fileSplitterFetch[nPos.length-1].start(); 0seCQANd  
]*0zir/  
[|nK5(e9  
//等待子线程结束 E7uIur=g!  
//int count = 0; vhe Y F@  
//是否结束while循环 TvU z^  
boolean breakWhile = false; |x}TpM;ni  
1XGg0SC  
Cfi{%,em  
while(!bStop) Jh"[ug  
{ !3b& S4  
write_nPos(); :.:^\Q0  
Utility.sleep(500); oW^b,{~V  
breakWhile = true; ZrN(M p  
&;PxDlY5  
JE.$]){  
for(int i=0;i<nStartPos.length;i++) $AK ^E6  
{ H%_^Gy8f  
if(!fileSplitterFetch.bDownOver) q"d9C)Md  
{ vs@d)$N  
breakWhile = false; ETDWG_H |  
break; :V/".K-:J  
} 6H#: rM  
} Ycr3$n]e  
if(breakWhile) V U3RFl  
break; ~&?([}A  
\@Wv{0a(  
>S5J^c  
//count++; pW]j.JM  
//if(count>4) WjV Bz   
// siteStop(); JVAyiNIH>M  
} +M j 6.X  
;lMvxt:  
@-@Coy 4Tt  
System.err.println("文件下载结束!"); !6/UwPs  
} {vu\qXmMv  
catch(Exception e){e.printStackTrace ();} oO2DPcK  
} ?9 huuJ s7  
AR| 4^  
Nd(,oXa~  
//获得文件长度 Tm %5:/<8  
public long getFileSize() `d <`>  
{ Q{/z>-X\x  
int nFileLength = -1; t=%zY~P  
try{ \Ec<ch[)c  
URL url = new URL(siteInfoBean.getSSiteURL()); sI,cX#h&Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wNa5qp 0  
httpConnection.setRequestProperty("User-Agent","NetFox"); =!TUf/O-  
E\iK_'#  
?P9aXwc  
int responseCode=httpConnection.getResponseCode(); K^WDA])  
if(responseCode>=400) %.bDK}  
{ *HrEh;3^J  
processErrorCode(responseCode); }*x1e_m}H  
return -2; //-2 represent access is error BM :x`JY  
} N*gJu  
/k.0gYD  
E '6>3n  
String sHeader; \h ~_<)  
#*(}%!rD*  
!vz'zy)7  
for(int i=1;;i++) hFV,FBsAO  
{ 6,t6~Uo/  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); & SXw=;B  
//Utility.log(in.readLine()); rm-d),Zt  
sHeader=httpConnection.getHeaderFieldKey(i); M=,pn+}y>  
if(sHeader!=null) %&L1 3:  
{ V.B@@ ;  
if(sHeader.equals("Content-Length")) 6uE20O<z]  
{ k_pv6YrE  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); poz_=,c  
break; <H-Nft>O  
} kpgvAKyx  
} QE]'Dc%  
else Ts!'>_<Je  
break; 4[lFur H  
} !2t7s96  
}  ~,lt^@a  
catch(IOException e){e.printStackTrace ();} ')jItje|  
catch(Exception e){e.printStackTrace ();} y 4i3m(S  
R ]Ev=V'U  
:1+Aj (  
Utility.log(nFileLength); @.;+WQE  
{!Qu(%  
^4sfVpD2!  
return nFileLength; mSYjc)z  
} M`Y^hDl6  
%lCZ7z2o  
7}iv+rQ  
//保存下载信息(文件指针位置) 66val"^W  
private void write_nPos() [Uup5+MCv  
{ )+ <w>pc  
try{ H(y`[B,}*  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \%7*@&  
output.writeInt(nStartPos.length); /,G `V  
for(int i=0;i<nStartPos.length;i++) TPp]UG  
{ xpdpD  
// output.writeLong(nPos); 1T|f<ChIF<  
output.writeLong(fileSplitterFetch.nStartPos); eB0exPz%  
output.writeLong(fileSplitterFetch.nEndPos); <8WFaP3,  
} (3n "a'  
output.close(); snaAn?I4  
} "0eX/ rY%  
catch(IOException e){e.printStackTrace ();} oc1BOW z  
catch(Exception e){e.printStackTrace ();} |~Dl<#58  
} ' i+L  
tpWGmj fo>  
xQsxc  
//读取保存的下载信息(文件指针位置) 3=enk0$  
private void read_nPos() ;!<}oZp{  
{ OnTe_JML  
try{ 5dj" UxH  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]\*^G@HA2  
int nCount = input.readInt(); 3d}v?q78  
nStartPos = new long[nCount]; NQ{(G8x9  
nEndPos = new long[nCount]; F`g(vD >  
for(int i=0;i<nStartPos.length;i++) H07\z1?.K  
{ #eW T-m  
nStartPos = input.readLong(); `n&:\Ib  
nEndPos = input.readLong(); zQ,rw[C"W  
} R4p Pt  
input.close(); .UP h  
} `7/(sX.  
catch(IOException e){e.printStackTrace ();} KF(H >gs  
catch(Exception e){e.printStackTrace ();} 4aO/^Hl  
} =:rg1wo"c  
-,8LL@_  
8lusKww  
private void processErrorCode(int nErrorCode) SAP/jD$5]>  
{ N{%7OG  
System.err.println("Error Code : " + nErrorCode); 8'PZA,CW  
} 6n]+(=  
BqNsW (+  
B=0^Rysg  
//停止文件下载 5/"$ _7"{a  
public void siteStop() [=K lDfU=  
{ Qx)b4~F?  
bStop = true; zu d_BOq{f  
for(int i=0;i<nStartPos.length;i++) vT?^#  
fileSplitterFetch.splitterStop(); :[CV_ME.;  
sF{~7IB  
a7g;8t-&   
} k%6CkC w  
} <- \|>r Q  
//负责部分文件的抓取 6?a`'&  
**FileSplitterFetch.java A-!e$yz>  
*/ aqON6|6K  
package NetFox; zj7ta[<tr  
}zGx0Q  
Tz1^"tx9  
import java.io.*; ?Bf>G]zx  
import java.net.*; r `PJb5^\|  
AR [m+E  
0:V /z3?  
public class FileSplitterFetch extends Thread { $cSUB  
B%tF|KKj  
$7q3[skH  
String sURL; //File URL 4aHogheg  
long nStartPos; //File Snippet Start Position nQc,^A)I  
long nEndPos; //File Snippet End Position +4 k=Y  
int nThreadID; //Thread's ID 4Fg2/O_3  
boolean bDownOver = false; //Downing is over x*1wsA  
boolean bStop = false; //Stop identical z$J m1l  
FileAccessI fileAccessI = null; //File Access interface P) vD?)Q  
FCt<h/  
JX&U?Z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WFF?VBT'^  
{ 3m>YR-n$  
this.sURL = sURL; 7${<u0((!  
this.nStartPos = nStart; 7DAP_C  
this.nEndPos = nEnd; w5>[hQR\  
nThreadID = id; .8YxEnXw)(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RBQ8+^  
} h4]^~stI  
iwF_'I$#N  
'WW:'[Syn'  
public void run() @} Ig*@  
{ 0=>$J WF  
while(nStartPos < nEndPos && !bStop) Qj^Uz+b  
{ Wj.t4XG!  
QXb2jWz  
Z!g6uV+.5  
try{ bB$f=W!m%  
URL url = new URL(sURL); p]kEH\ sh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @_do<'a  
httpConnection.setRequestProperty("User-Agent","NetFox"); }#^C j;  
String sProperty = "bytes="+nStartPos+"-"; 9"P+K.%  
httpConnection.setRequestProperty("RANGE",sProperty); M+%Xq0`T  
Utility.log(sProperty); <@Q27oEuA  
d]0:r]e  
w;,34qbf  
InputStream input = httpConnection.getInputStream(); & 'u|^d  
//logResponseHead(httpConnection); it}h8:^<  
b<tV>d"Fv  
<D |&)/#  
byte[] b = new byte[1024]; Kg 6J:HD49  
int nRead; 9VW/Af  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ek&~A0k_o  
{ |.@!CqJ  
nStartPos += fileAccessI.write(b,0,nRead); T1C_L?L  
//if(nThreadID == 1) :Q`Of}#  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pB:XNkxL  
} E ASnh   
T 6D+@i  
boojq{cvYA  
Utility.log("Thread " + nThreadID + " is over!"); BeUyt  
bDownOver = true; ] hT\"5&6  
//nPos = fileAccessI.write (b,0,nRead);  }#m9Q[  
} vaeQ}F  
catch(Exception e){e.printStackTrace ();} h~#iGs  
} m.+h@  
} OH/9<T?  
*J4!+GD  
^os_j39N9  
//打印回应的头信息 {dF@Vg_n  
public void logResponseHead(HttpURLConnection con) L-Q8iFW'  
{ Sqa9+' [  
for(int i=1;;i++) ]zYIblpde  
{ f7*Qa!!2p]  
String header=con.getHeaderFieldKey(i); :u7BCV|yr  
if(header!=null) =K:[26  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $z_yx `5  
Utility.log(header+" : "+con.getHeaderField(header)); :aOR@])>o  
else ^=x/:0  
break; |Z>-<]p9g  
} i "V.$|,  
} )5@P|{FF  
ykC3Z<pI.  
E+Bc>xl@ m  
public void splitterStop() {z>!Fw  
{ $6n J+  
bStop = true; wNUT0+  
} _WNbuk0  
bpc1> ?  
8oE`>Y  
} J!om"h  
x{;{fMN1  
5$ik|e^:y  
/* u4hn9**a1  
**FileAccess.java Mst%]@TG  
*//文件访问(定位,写) }-tJ.3Zw  
package NetFox; >12jUm)  
import java.io.*; _S) K+C|@  
frcX'M}%  
bkdXBCBx?  
public class FileAccessI implements Serializable{ 5ih>x3S1/  
+[ ?!@)  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6c!F%xU}  
RandomAccessFile oSavedFile; #H7 SLQr\  
long nPos; JLm3qIC  
Dspvc  
|-ZML~2S=h  
public FileAccessI() throws IOException vP,pK=5  
{ Zd-qBOB2L  
this("",0); 6 5zx<  
} hr]+ 4!/  
Vja 4WK*  
Un8' P8C  
public FileAccessI(String sName,long nPos) throws IOException (EcP'F*;;y  
{ pT=^o  
oSavedFile = new RandomAccessFile(sName,"rw"); NlF*/Rs  
this.nPos = nPos; !BVCuuM>w  
oSavedFile.seek(nPos); 'TYO-'aC  
} -n 7 @r  
lq.:/_m0  
fDDpR=  
public synchronized int write(byte[] b,int nStart,int nLen) < h#7;o  
{ ovN3.0tAI  
int n = -1; HsYzIQLL  
try{ |"K%Tvxe  
oSavedFile.write(b,nStart,nLen); Do(G;D`h+_  
n = nLen; '|gsmO  
} 7l7VT?<:  
catch(IOException e) ; s(bd#Q  
{ sq=EL+=j  
e.printStackTrace (); b; of9hY  
} f&$Bjq  
v FL$wr  
s 4rva G@a  
return n; jUE:QOfRib  
} ;R 6f9tu2  
m|fcWN[  
AO`@ &e]o  
} Rng-o!   
HIw)HYF 2  
3~fi#{  
/* :JSxsA6 k  
**SiteInfoBean.java 3F"vK  
*/ SOG(&)b  
package NetFox; GI{EP&C  
%!iqJ)*~  
@"s<0T^H  
public class SiteInfoBean { b$;oty9Y  
UA'bE~i  
-Y+pLvG*  
private String sSiteURL; //Site's URL g<;pyvq|:  
private String sFilePath; //Saved File's Path 0fstEExw  
private String sFileName; //Saved File's Name lO\HchG zB  
private int nSplitter; //Count of Splited Downloading File WCd: (8B  
mKtMI!FR  
,W+=N"`a'  
public SiteInfoBean() H,c1&hb/w  
{//nSplitter的缺省值为5 ]?_~QE`  
//default value of nSplitter is 5 1VYH:uGuAU  
this("","","",5); $MvKwQ/  
} zq + 2@"q  
nN$.^!;&  
}s?3   
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @ *Jbp  
{ *[cCY!+Qy  
sSiteURL= sURL; $|Ol?s  
sFilePath = sPath; R/1e/t  
sFileName = sName; ri-&3%%z<  
this.nSplitter = nSpiltter; hfJ&o7Dt  
9q0s  
x]YzVJ=Y  
} kj|Oj+&  
v1i-O'  
F ]X<q uuL  
public String getSSiteURL() ;4-$C=&  
{ 3KqRw (BK  
return sSiteURL; !DA4q3-U>>  
} q;R&valn  
 cL .z{  
2Rys:$  
public void setSSiteURL(String value) enxb pq#  
{ gWjYS#D  
sSiteURL = value; Vc(kw7  
} _fgsHx>l7  
B!<B7Q  
|{|B70v3Co  
public String getSFilePath() R7b-/ !L  
{ Vxrj(knck,  
return sFilePath; M&=SvM.f  
} 7]So=% q  
?v,c)  
tMdSdJ8  
public void setSFilePath(String value) V1P]pP  
{ |63uoRr  
sFilePath = value; ~9rNP{+  
} D4"<suU|.  
k2lo GvBJ  
F+VNrt-  
public String getSFileName() DNDzK iMk  
{ VQf^yq  
return sFileName; Uth+4Aq  
} $C=XSuPNK  
c{`!$Z'k<  
lNc0znY  
public void setSFileName(String value) PC"=B[OlJ  
{ 4D 5Wse  
sFileName = value; D$KP>G  
} | J'k 9W"  
RpU i'  
(Of`VT3ZOA  
public int getNSplitter() $#%R _G]  
{ l %zbx"%x  
return nSplitter; iiuT:r  
} x]Nx,tt  
gCYe ^KJ  
|H8C4^1Rq  
public void setNSplitter(int nCount) [V /f{y~ {  
{ )6"p@1\u  
nSplitter = nCount; BGVnL}0  
} }'{"P#e8"q  
} X9c<g;  
73 1RqUR  
>8{{H"$;(  
/* bCTN^  
**Utility.java 3 P75:v  
*/ X:f5t`;  
package NetFox; %d-WQwJ  
(-1{W^(  
NH5sV.vvc  
public class Utility { a{^ 2c!  
[Ous|a[)o  
[[w-~hHH-  
public Utility() Ymnh%wS  
{ Qru&lAYc<  
3XUVUd~  
Xsn M}  
} sJQ~ :p0e  
UZ<.R"aK  
//线程睡眠 C_ ;nlG6  
public static void sleep(int nSecond) VNz? e&>  
{ _ZJQE>]nWu  
try{ Nz"K`C>/  
Thread.sleep(nSecond); %c$|.TkX  
} `o9:6X?RA  
catch(Exception e) @ZYJY  
{ 9;n*u9<  
e.printStackTrace (); Uv?^qe0=  
} 1QhQ#`$<1  
} K)1Lg? j  
npytb*[|c  
//日志 c9@3=6S/  
public static void log(String sMsg) ?&qQOM~b-\  
{ 9%R"(X)  
System.err.println(sMsg); nT~XctwF  
} ?|NsaW  
A3HN Mz  
j,%i.[8S  
public static void log(int sMsg) [SKDsJRPP  
{ O\oRM2^u}  
System.err.println(sMsg); dA2@PKK  
} Gys-Im6>~@  
} xz} CqPJ#  
; X+.Ag  
V\n!?1{kdF  
/* uARkf'  
**TestMethod.java N*PJ m6-  
*/ d@8: f  
package NetFox; vN]_/T+  
R:'&>.AUw  
,\\=f#c=  
public class TestMethod { < )_#6)z:  
%PPy0RZ^  
xU{0rM"  
public TestMethod() dB&<P[$+8  
{ ///xx/weblogic60b2_win.exe FKe/xz  
try{ ,T ^A?t  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DqI"B  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "9X(.v0ze  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jv%)UR.]  
fileFetch.start(); qv2J0'd'.  
} C>-}BeY!  
catch(Exception e){e.printStackTrace ();} S,,Wb &A$  
iB~dO @  
^%6f%]_  
} QYj 4D  
sVnq|[ /  
W<O/LHKHdn  
public static void main(String[] args) !K=$Q Uq  
{ pvWj)4e  
new TestMethod(); ;Hp78!#,  
} 9N2.:<so  
} N!tNRMTi  
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