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http断点续传简单实现(java)

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/* bzg C+yT  
**SiteFileFetch.java tK#R`AQ  
*/ K5""%O+  
package NetFox; :{lwz#9V  
import java.io.*; GIC1]y-'  
import java.net.*; ZCiCZ)oc  
\8`?ir q"  
<xOv8IQ|  
public class SiteFileFetch extends Thread { wQkM:=t5  
/ZLY@&M  
xO~ ElzGm  
SiteInfoBean siteInfoBean = null; //文件信息Bean  N;7/C  
long[] nStartPos; //开始位置 xmW~R*^  
long[] nEndPos; //结束位置 (\V i _  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6cQgp]%  
long nFileLength; //文件长度  4M'>oa  
boolean bFirst = true; //是否第一次取文件 gq?:n.;TY  
boolean bStop = false; //停止标志 +6m.f,14q  
File tmpFile; //文件下载的临时信息 d0 cL9&~qW  
DataOutputStream output; //输出到文件的输出流 Qzi?%&  
Szus*YL7  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) /7Q|D sa  
public SiteFileFetch(SiteInfoBean bean) throws IOException %u -x9  
{ W U(_N*a  
siteInfoBean = bean; E8Dh;j  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); yU?jmJ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 1H)mJVIKkB  
if(tmpFile.exists ()) ~Bd=]a$mj  
{ $o^Z$VmL  
bFirst = false; ,Kit@`P%  
read_nPos(); 8`Ya7c>  
} cNs'GfD}  
else !3v&+Jrf6  
{ vqf$("  
nStartPos = new long[bean.getNSplitter()]; tYS4"Nfb+  
nEndPos = new long[bean.getNSplitter()];  Cs,H#L  
} {pzj@b 1S  
0c_xPBbB+  
W :w~ M'o  
s}D>.9  
} ]BQYVx/  
@ [$_cGR7  
y4V:)@ P  
public void run() s0kp(t!fiu  
{ S}m_XR]  
//获得文件长度 V7ph^^sC}  
//分割文件 : Mf"   
//实例FileSplitterFetch $Y$9]G":  
//启动FileSplitterFetch线程 #el27"QP0  
//等待子线程返回 NE995;  
try{ iyskADS  
if(bFirst) s?SspuV  
{ >4 OXG7.&f  
nFileLength = getFileSize();  ao(T81  
if(nFileLength == -1) ~MpikBf  
{ %|Ps|iV  
System.err.println("File Length is not known!"); k3\N.@\  
} D}-.<  
else if(nFileLength == -2) 98m|&7  
{ =;}W)V|X)S  
System.err.println("File is not access!"); |(7}0]BP0  
} nK&]8"  
else ~j0rORy]  
{ !-gU~0  
for(int i=0;i<nStartPos.length;i++) ,Q`qnn&  
{ K*6"c.D  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); So:X!ljN(e  
} >}5?`.K~Q*  
for(int i=0;i<nEndPos.length-1;i++) X/!_>@`7?  
{ xad`-vw  
nEndPos = nStartPos[i+1]; Jh[0xb  
} Onmmcem  
nEndPos[nEndPos.length-1] = nFileLength; Bd>~F7VWs  
} @Mk`Tl  
} [ oWkd_dK  
Bqx5N"  
%!|w(Povq  
//启动子线程 }d$-:l ,w  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  EM ,C  
for(int i=0;i<nStartPos.length;i++) Tc2.ciU  
{ 7#8Gn=g  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f60w%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b@:OlZ~ %  
nStartPos,nEndPos,i); c]=2>ov)hR  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ">A<%5F2  
fileSplitterFetch.start(); 5&Oc`5QD  
} 4aayMS !#  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rk=D5E7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^xo<$zn  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .nV2 n@SR  
nEndPos = " + nFileLength); Ebg8qDE  
// fileSplitterFetch[nPos.length-1].start(); 5/H,UL  
,'#TdLe  
|dRVSVN  
//等待子线程结束 3"fDFR  
//int count = 0;  Et>#&Nw8  
//是否结束while循环 qT O6I5u  
boolean breakWhile = false; OLw]BJXYaE  
xm'9n?  
@sXFu[!U  
while(!bStop) _vQ52H,  
{ D0. )%  
write_nPos(); %E?Srs}j  
Utility.sleep(500); Vns3859$8  
breakWhile = true;  vSzpx  
t0)1;aBZ  
VK}4 <u  
for(int i=0;i<nStartPos.length;i++) 8&<:(mAP  
{ rTD+7 )E  
if(!fileSplitterFetch.bDownOver) O"m7r ds  
{ wjarQog5Y  
breakWhile = false; =u~nLL  
break; Lx"GBEkt7  
} q*!R4yE;C  
} )m%uSSx#  
if(breakWhile) %1z;l.c  
break; MqmQ52HR  
Z:4/lx7Bq  
,GbmL8P7Y  
//count++;  56.!L  
//if(count>4) 0RR|!zEu  
// siteStop(); m_NX[>&Y3  
} `FHudSK  
.?>Cav9:  
ldv@C6+J  
System.err.println("文件下载结束!"); <O#&D|EMd|  
} ^BsT>VSH6  
catch(Exception e){e.printStackTrace ();} *dBy<dIy  
} 3bEcKA_z(  
d\z6Ob"t  
=j7Du[?Vu  
//获得文件长度 (f/(q-7VWt  
public long getFileSize() -YoL.`s1   
{ w,{h9f  
int nFileLength = -1; XcR=4q|7  
try{ ^'UM@dd?!  
URL url = new URL(siteInfoBean.getSSiteURL()); N['DqS =  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1v@#b@NXM7  
httpConnection.setRequestProperty("User-Agent","NetFox"); W/'1ftn?D  
Mw[3711v  
j,n:%5P\v  
int responseCode=httpConnection.getResponseCode(); Xfiwblg  
if(responseCode>=400) *yq65yZi5  
{ {q>%Sr]9  
processErrorCode(responseCode); 1\hLwG6Jj  
return -2; //-2 represent access is error 0Tj,TF  
} CTMC78=9}  
Nc[@QC{  
LF|0lAr  
String sHeader; ^:9a1{L[  
r" H::A  
1;B~n5C.   
for(int i=1;;i++) \aSP7DzqQ  
{ m^X51,+<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )g5?5f;  
//Utility.log(in.readLine()); ;0DoZ  
sHeader=httpConnection.getHeaderFieldKey(i); 9>RkFV  
if(sHeader!=null) tBo\R?YRs  
{ An2 >]\L  
if(sHeader.equals("Content-Length")) -cqE^qAdX  
{ z?/_b  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a~}q]o?j  
break; $4bc!  
} 7FX4|]  
} Pz)lq2Zm9  
else h nydH-;cz  
break; @]uqC~a^  
} g*k)ws  
} AXyXK??  
catch(IOException e){e.printStackTrace ();} B,b8\\^k|  
catch(Exception e){e.printStackTrace ();} "Eh=@?]S_  
J)nK9  
mhbczVw  
Utility.log(nFileLength); Bdo{zv&A  
y r (g/0  
5F kdGF  
return nFileLength; F5)`FM^R  
} x&B&lFmo 8  
!do`OEQKR  
KEAXDF&#  
//保存下载信息(文件指针位置) vCa8`m  
private void write_nPos() 3%v)!dTa<^  
{ ==Gc%  
try{ 4uF.kz-cg  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8Vu@awz{L  
output.writeInt(nStartPos.length); ^ h=QpH  
for(int i=0;i<nStartPos.length;i++) 2D 4,#X  
{ LV}R 9f  
// output.writeLong(nPos); SYJO3cY  
output.writeLong(fileSplitterFetch.nStartPos); -()WTdIy  
output.writeLong(fileSplitterFetch.nEndPos); Xv1vq -cM  
} m*^)#  
output.close(); 7_~ A*LM  
} _i_='dsyW/  
catch(IOException e){e.printStackTrace ();} C qd\n#d/~  
catch(Exception e){e.printStackTrace ();} d/_D|ivZ=  
} ki1(b]rf  
x0j5D  
P&`%VW3E  
//读取保存的下载信息(文件指针位置) v9(5H Y  
private void read_nPos() RZ6y5  
{ rr# nBhh8  
try{ 9r%fBiSk  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t]K20(FSN  
int nCount = input.readInt(); B{Q}^Mcxy  
nStartPos = new long[nCount]; <rC%$tr  
nEndPos = new long[nCount]; o.KnDY  
for(int i=0;i<nStartPos.length;i++) U[C>Aoze  
{ 5|*{~O|  
nStartPos = input.readLong(); d4o ^+\  
nEndPos = input.readLong(); 2A_1E \  
} MQ,K%_m8  
input.close(); IQ&PPC  
} eV7;#w<]  
catch(IOException e){e.printStackTrace ();} Vr2A7kq  
catch(Exception e){e.printStackTrace ();} a4:GGzt  
} 0ix(1`Z  
>u=  
tN#C.M7.'7  
private void processErrorCode(int nErrorCode) C?qRZB+W#  
{ 1UP {j`-K|  
System.err.println("Error Code : " + nErrorCode); 6_mi9_w  
} h<9vm[.  
w/@ZPBRo]  
n#!c!EfG  
//停止文件下载 }s,NM%oI  
public void siteStop() F ~A $7  
{ f' A$':Y  
bStop = true; !MoAga_ j  
for(int i=0;i<nStartPos.length;i++) ^4=#, K  
fileSplitterFetch.splitterStop(); \,S |>CPQ  
9'MGv*Ho  
ni;)6,i  
} z;JV3) E  
} @]qP:h.  
//负责部分文件的抓取 = l(euBb  
**FileSplitterFetch.java 1PY]Q{r  
*/ zPnb_[YF  
package NetFox; ^ZMbJe%L  
rrL.Y&DTK  
[,Ehu<mEK  
import java.io.*; LR=Ji7  
import java.net.*; $RDlM  
 IuY9Q8  
etX@z'H  
public class FileSplitterFetch extends Thread { /8; m.J>bf  
/&Q{B f  
TcZ.5Oe6h#  
String sURL; //File URL >pu4G+M  
long nStartPos; //File Snippet Start Position /3s&??{tv  
long nEndPos; //File Snippet End Position HV%/baX]  
int nThreadID; //Thread's ID xPZ>vCg  
boolean bDownOver = false; //Downing is over 1 Uup.(  
boolean bStop = false; //Stop identical *}2L4]  
FileAccessI fileAccessI = null; //File Access interface ]i {yJ)i  
vW?\bH7}I  
kZe<<iv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <7P[)X_  
{ q>_<\|?%x  
this.sURL = sURL; mZ71_4X#  
this.nStartPos = nStart; *RkUF!)(  
this.nEndPos = nEnd; }MaY:PMA  
nThreadID = id; WW:G( \`  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^ ]9K>}  
} Snk+ZQ-  
bK:U:vpYm  
,rMDGZm?  
public void run() 6Vnq|;W3Zv  
{ $udhTI#,  
while(nStartPos < nEndPos && !bStop) 44KoOY_  
{ N3"JouP  
<0d2{RQ;  
40?RiwwD  
try{ qyM/p.mP  
URL url = new URL(sURL); J>(X0@eWz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TuQGF$n@  
httpConnection.setRequestProperty("User-Agent","NetFox"); QIiy\E%  
String sProperty = "bytes="+nStartPos+"-"; h0<PQZJ  
httpConnection.setRequestProperty("RANGE",sProperty); ROFZ*@CH<  
Utility.log(sProperty); q-!H7o  
F85_Lz4  
'=0}2sF>  
InputStream input = httpConnection.getInputStream(); OZ\6qMH3e  
//logResponseHead(httpConnection); `,]Bs*~  
H,}&=SCk  
j n^X{R\  
byte[] b = new byte[1024]; %,bD| NKp  
int nRead; - rO34l  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Db"mq'vT  
{ UDEGQ^)Xz|  
nStartPos += fileAccessI.write(b,0,nRead); t@!n?j I  
//if(nThreadID == 1) ?%5VaxWJ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O cL7] b0  
} e |Ri  
;M?)-dpZ  
<>6j>w_|  
Utility.log("Thread " + nThreadID + " is over!"); rpKZ>S|7+)  
bDownOver = true; nJe}U#  
//nPos = fileAccessI.write (b,0,nRead); =zFROB\  
} AJ7w_'u=@  
catch(Exception e){e.printStackTrace ();} %)j&/QdzF&  
} v@$N,g  
} 9JFN8Gf*)  
m?kiGC&m  
! AwMD  
//打印回应的头信息 uG\~Hxqw7O  
public void logResponseHead(HttpURLConnection con) *I 1H  
{ X%b1KG|#(  
for(int i=1;;i++) %mC@}  
{ ny{C,1QG  
String header=con.getHeaderFieldKey(i); L('1NN 2  
if(header!=null) (fpz",[  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )'kpO>_G  
Utility.log(header+" : "+con.getHeaderField(header)); _V$'nz#>e  
else 4<Vi`X7[F  
break; M FIb-*wT  
} V}V->j*  
} !Ubm 586!  
necY/&Ld-  
2iNLm6"  
public void splitterStop() W{;Qi&^ca  
{ (p2`ofj  
bStop = true; :u4|6?  
} AA5G` LiT  
a/ A c^!(  
ko@ej^  
} L"ho|v9:  
`N\ ^JAGW  
:9QU\{2  
/* g`pq*D  
**FileAccess.java mn@1&#c4y  
*//文件访问(定位,写) Ze V@ X  
package NetFox; S"!6]!~^  
import java.io.*; ZN8j})lE  
YNBM\Q  
r~,y3L6ic  
public class FileAccessI implements Serializable{ X9| Z ?jJ  
R&cT Md  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vgeqH[:  
RandomAccessFile oSavedFile; *aCL/:  
long nPos; =d8Rij-  
+0Q   
:^y!z1\2(7  
public FileAccessI() throws IOException lgews"  
{ WX4sTxJK  
this("",0); TO Hz3=  
} >SXSrXyYX  
k>ErD v8  
b/_Zw^DPC  
public FileAccessI(String sName,long nPos) throws IOException `Moo WG  
{ \9[vi +T  
oSavedFile = new RandomAccessFile(sName,"rw"); RQ E]=N  
this.nPos = nPos; cb_C2+%8NA  
oSavedFile.seek(nPos); CtY-Gs  
} kQ>2W5o-d-  
|5vcT, A  
{($bz T7c  
public synchronized int write(byte[] b,int nStart,int nLen) Mqr]e#"o  
{ F?6kkLS/  
int n = -1; EA~xxKq  
try{ d[t0K]  
oSavedFile.write(b,nStart,nLen); _s;y0$O  
n = nLen; Q# hRnM  
} 6Rfv3  
catch(IOException e) !` 1h *}  
{ oEX,\@+u  
e.printStackTrace (); \kQ)fk]^  
}  ]~;*9`:  
"-f]d~P>  
k^}[+IFJ  
return n; -f|/#1  
} SNqSp.>-U"  
1NP  
~DD _n  
} "]"0d[d  
kZF]BPh.  
\oPe" k=  
/* _4>DuklH,  
**SiteInfoBean.java ;"&?Okz  
*/ p&Qb&nWk<  
package NetFox; .OJG o<#$f  
0se%|Z|8  
F/2cQ .u2  
public class SiteInfoBean { tz]0F5  
o'lG9ePM|  
`p\%ha!,w  
private String sSiteURL; //Site's URL /D"T\KNWr  
private String sFilePath; //Saved File's Path im*sSz 0 (  
private String sFileName; //Saved File's Name 7=fM}sk  
private int nSplitter; //Count of Splited Downloading File "\*)KH`C  
a>GA=r  
^x&x|ckR!  
public SiteInfoBean() DG;u_6;JR  
{//nSplitter的缺省值为5 =\]gL%N-|  
//default value of nSplitter is 5 Gxd/t#;  
this("","","",5); 4&NB xe  
} "5eD >!  
 _ %mm  
W_XFTqp^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2M+RA}dX  
{ @ fMlbJq  
sSiteURL= sURL; G5qsnTxUJ  
sFilePath = sPath; ^U~Er'mT  
sFileName = sName; Wqv7  
this.nSplitter = nSpiltter; ~"S5KroN  
m LajiZ Bf  
o2(w  
} AkW,Fp1e  
-v9(43  
cPIyD?c  
public String getSSiteURL() L^e*_q2d:>  
{ 2>"{El|PbN  
return sSiteURL; HV!P]82Pa  
} Jha*BaD~N  
U+VJiz<!  
<@`K^g;W  
public void setSSiteURL(String value) ]}SV%*{ %  
{ R{}_Qb  
sSiteURL = value; !& c%!*  
} > X  AB#  
(NUXK  
f]1 $`  
public String getSFilePath() o,k#ft<  
{ +PYR  
return sFilePath; p3fV w]N  
} >]}VD "\  
RCqL~7C+ k  
3Dc^lfn  
public void setSFilePath(String value)  ~@@t-QY  
{ vasw@Uto)  
sFilePath = value; toF6 Z  
} 'NWvQR<X  
BfCib]V9C  
=SJ[)|  
public String getSFileName() |QzJHP @  
{ ' Sd&I:?  
return sFileName; h%:wIkZ/  
} a:|]F|  
b c .Vy  
CWs;1`aP  
public void setSFileName(String value) *RkvM?o@jC  
{ ~=wBF  
sFileName = value; ,hK =x  
} mp3Dc  
7TAoWD3  
a w~a /T:  
public int getNSplitter() JF &$'  
{ k'$7RjCu  
return nSplitter; lItr*,A]  
} =uwG.,lC  
BvlY\^  
6:r1^q6A9L  
public void setNSplitter(int nCount) /x-tl)(s=  
{ ICoZ<;p  
nSplitter = nCount; FlS)m`  
} ?Wt_Obl  
} Rpcnpo  
2b {Y1*  
EI9Yv>7d{  
/* yyR@kOGga  
**Utility.java Zfu" 8fX  
*/ W6B o\UK  
package NetFox; !/&~Feb  
tORDtMM9+  
GmGq69]J*  
public class Utility { n;b 9f|&z  
fZd~},X  
:+DAzjwO<  
public Utility() :?%_JM5U  
{ >fR#U"KPAB  
b=Sl`&A  
mR{%f?B  
} y(#F&^|  
hYCyc -W  
//线程睡眠 GLl@ 6S>v  
public static void sleep(int nSecond) ZG)C#I1;O  
{ Jf2:[ Mq  
try{ N_!Zn"J  
Thread.sleep(nSecond); of<>M4/g4y  
} Iq": U  
catch(Exception e) 9aqFdlbY  
{ ~?A,GalS  
e.printStackTrace (); cmh/a~vYaY  
} I|[aa$G  
} ?yz}  
NOmSLIgt7  
//日志 j1toV$)P  
public static void log(String sMsg) 28+ Sz>SP  
{ y+iuA@WCv  
System.err.println(sMsg); 0H.B>: pv  
} fs]Zw mA^  
&sA6o"h~  
~pSD|WX  
public static void log(int sMsg) &9] [ ~$  
{ .J\U|r  
System.err.println(sMsg); >-y&k^a=  
} <Q-ufF85)  
} Mz{ Rh+gS  
:S7yM8 b`  
skP_us~  
/* /C8(cVNZ  
**TestMethod.java W%Zyt:H`  
*/ Zk;;~ESOU  
package NetFox; kk5i{.?[  
1 }q[8q  
vrW9<{  
public class TestMethod { k0D&F;a%  
! xqG-rd '  
kAk,:a;P  
public TestMethod() R QO{fC  
{ ///xx/weblogic60b2_win.exe NtOR/*  
try{ VZlvmN  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E[Io8|QA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %J%gXk}]  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :~)Q]G1Nj  
fileFetch.start(); $v oyXi`*  
} +#H8d1^5  
catch(Exception e){e.printStackTrace ();} izW l5}+'B  
3S2'JOTY  
~ pdf'  
} \M532_w  
6k3l/~R  
fAUsJ[  
public static void main(String[] args) s* YFN#Wuc  
{ ujWHO$uz!  
new TestMethod(); S@"=,Xj M  
} K ;xW/7?  
} ta6 WZu  
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