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http断点续传简单实现(java)

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/* UXdnN;0  
**SiteFileFetch.java "3Lq/mJYnZ  
*/ u$MXO].Q  
package NetFox; P2t9RCH  
import java.io.*; n#dvBK0M  
import java.net.*;  Qk)E:  
u]$e@Vw.  
[vNaX%o  
public class SiteFileFetch extends Thread { j96\({;k  
] v8.ym  
MRb6O!$`C  
SiteInfoBean siteInfoBean = null; //文件信息Bean "T~ce@  
long[] nStartPos; //开始位置 4COo~d  
long[] nEndPos; //结束位置 )1ct%rue  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 2l.qINyz  
long nFileLength; //文件长度 ~/R bYvyA  
boolean bFirst = true; //是否第一次取文件 y7@q]~%  
boolean bStop = false; //停止标志 z:JQ3D7/we  
File tmpFile; //文件下载的临时信息 p O O4fc  
DataOutputStream output; //输出到文件的输出流 )Zbrg~-@  
]N4?*S*jd)  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) {~0r3N4Zl  
public SiteFileFetch(SiteInfoBean bean) throws IOException 9J(jbJ7p  
{ k%TjRf{p  
siteInfoBean = bean; lG/h[  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [39  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); AD0pmD  
if(tmpFile.exists ()) tGVC"a  
{ L; (J6p]h  
bFirst = false; V")u y&Ob  
read_nPos(); Ef"M e(  
} Qs #7<NQ  
else --BS/L-  
{ ? f>pKe  
nStartPos = new long[bean.getNSplitter()]; %7 [ Z/U=  
nEndPos = new long[bean.getNSplitter()]; UR' P,  
} .{ -C*  
.j l|? o  
/{sFrEMP\  
fKQq]&~ H  
} xwe^_7  
<xO" E%t  
 M_ii  
public void run() E5`KUMZkq  
{ ` Clh;  
//获得文件长度 ["} Yp  
//分割文件 6ntduXeNVh  
//实例FileSplitterFetch ^wTod\y  
//启动FileSplitterFetch线程 d"~-D;  
//等待子线程返回 ]O 8hkGa  
try{ E(/M?>t-  
if(bFirst) ]J)3y+;P  
{ m |%ly  
nFileLength = getFileSize(); 5* 3T+OK  
if(nFileLength == -1) $5v:z   
{ 9%6W_ 0>  
System.err.println("File Length is not known!"); 0.kQqy~5  
} Xm I63W*  
else if(nFileLength == -2) L.R4 iN  
{ )D>= \ Me  
System.err.println("File is not access!"); p&Ev"xhs  
} T(4OPiKu  
else Udl8?EVSz  
{ , 3p$Z  
for(int i=0;i<nStartPos.length;i++) Hy| X>Z  
{ % >}{SS  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); k%2Rv4)hU  
} "79"SSfOc  
for(int i=0;i<nEndPos.length-1;i++) t IO 'ky  
{ /+zzZnLl-M  
nEndPos = nStartPos[i+1]; WIkr0k  
} hsEQ6  
nEndPos[nEndPos.length-1] = nFileLength; #!RO,{FT  
} ,,o5hD0V9  
} dSq3V#Q  
Uh=@8v  
1?hx/02  
//启动子线程 Ubf@"B  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d@IV@'Q7u  
for(int i=0;i<nStartPos.length;i++) ;f l3'.S[  
{ "o6a{KY(  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]46#u=y~3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F!pgec%]'  
nStartPos,nEndPos,i); ccm(r~lhJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8 bpYop7 L  
fileSplitterFetch.start(); `%nj$-W:  
} 5ON\Ve_H  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D g~L"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Lj#K^c Ee  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ir\f _>7  
nEndPos = " + nFileLength); Pt^SlX^MM  
// fileSplitterFetch[nPos.length-1].start(); 3wf&,4`EX  
1Bhd-  
t~(|2nTO5  
//等待子线程结束 uFl19  
//int count = 0; Yp(F}<f?  
//是否结束while循环 Yv ZcG3@c3  
boolean breakWhile = false; ^oYudb^%  
&8R !`uh1  
ey ;94n:<  
while(!bStop) 5?M d  
{ w0(1o_F7.  
write_nPos(); 'j27.Ry.  
Utility.sleep(500); Htn''adg5  
breakWhile = true; &w7Ev21  
6X`i*T$.  
r< ~pSj  
for(int i=0;i<nStartPos.length;i++) 'En|-M5  
{ h =E)5&Z  
if(!fileSplitterFetch.bDownOver) eemw I  
{ 4/:}K>S_  
breakWhile = false; uW4wTAk;qh  
break; H)VzPe#{  
} S#{gCc  
} @})]4H  
if(breakWhile) s.qo/o\b  
break; @eOD+h'  
yuA+YZ  
|18h p  
//count++; y Nc"E  
//if(count>4) pS6p}S=1]  
// siteStop(); :Y)jf  
} ;FfDi*S7  
BWG*UjP M  
+p"}F PIK  
System.err.println("文件下载结束!"); ,C97|6rC  
} 97 eEqI$#  
catch(Exception e){e.printStackTrace ();} MFzJ 8^.1R  
} 6#gS`X23Y  
:plN<8  
pEp`Z,p  
//获得文件长度 Ef~Ar@4fA  
public long getFileSize() 56`Tna,t  
{ HY!R|  
int nFileLength = -1; u(W+hdTap=  
try{ ~OSgpM#O!T  
URL url = new URL(siteInfoBean.getSSiteURL()); X"Ca  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hI>vz"J  
httpConnection.setRequestProperty("User-Agent","NetFox"); Vl\8*!OL%  
cN 3 !wE  
ms%RNxU4:  
int responseCode=httpConnection.getResponseCode(); /?*GJN#  
if(responseCode>=400) 2&o jQhe  
{ -g\;B  
processErrorCode(responseCode); >K;DBy*  
return -2; //-2 represent access is error >h3m/aeNC  
} Mv?$zV"`#  
9,c_(%C  
?[VL 2dP0  
String sHeader; L'L[Vpx  
{16]8-pe  
j/p1/sJ[y  
for(int i=1;;i++) {3`cSm6c  
{ N> jQe  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /nWBol,  
//Utility.log(in.readLine()); F?+\J =LT  
sHeader=httpConnection.getHeaderFieldKey(i); {|{;:_.>  
if(sHeader!=null) "K c/Cs2[  
{ Rl{e<>O\^  
if(sHeader.equals("Content-Length")) lx\9Y8  
{ 5RsO^2V:  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >r\q6f#J4  
break; 4&kC8 [r  
} )lZoXt_3  
} g^: & Dh  
else l=PZlH y1G  
break; [nASMKK0  
} U!i1~)s  
} J!\oH%FJp  
catch(IOException e){e.printStackTrace ();} x/dyb.  
catch(Exception e){e.printStackTrace ();} "IN[(  
("KtJ  
1I?`3N  
Utility.log(nFileLength); Jo''yrJpB  
?[<#>,W  
f]48-X,^6  
return nFileLength; PH$C."Vv  
} @1N .;]|  
V}X>~ '%  
!nU|3S[b  
//保存下载信息(文件指针位置) *7o@HBbF  
private void write_nPos() N 9W,p 2  
{ bH.SUd)  
try{ m+Kl   
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z 4QL&?U  
output.writeInt(nStartPos.length); m6uFmU*<M}  
for(int i=0;i<nStartPos.length;i++) G=/^]E  
{ ^r~O*  
// output.writeLong(nPos); Cto>~pV  
output.writeLong(fileSplitterFetch.nStartPos); *,|x p  
output.writeLong(fileSplitterFetch.nEndPos); E#R1  
} f?$yxMw:@  
output.close(); X-*LA*xbN  
} :nOI|\ rC  
catch(IOException e){e.printStackTrace ();} y* :C~  
catch(Exception e){e.printStackTrace ();} {)(Mkm +d  
} <JIqkGeAi  
6 2#@Y-5  
U+R9bn   
//读取保存的下载信息(文件指针位置) xX|f{)<  
private void read_nPos() EU7nS3K)O~  
{ Z((e-T#,  
try{ /dO*t4$@?  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gO{$p q}  
int nCount = input.readInt(); Y-lwS-Ii  
nStartPos = new long[nCount]; U1`pY:P  
nEndPos = new long[nCount]; aJ@lT&.  
for(int i=0;i<nStartPos.length;i++) osc A\r  
{ %(|-+cLW+  
nStartPos = input.readLong(); `=S%!akj  
nEndPos = input.readLong(); |8tKN"QG  
} 2}XxRJ0   
input.close(); T"t.t%(8  
} Y9I|s{~  
catch(IOException e){e.printStackTrace ();} k!bG![Ie|  
catch(Exception e){e.printStackTrace ();} +@c$n`>)  
} 39MOqVc  
p2U6B  
Kn1T2WSAg  
private void processErrorCode(int nErrorCode) p( )LQT!  
{ X#Ob^E%J  
System.err.println("Error Code : " + nErrorCode); kZhd^H.  
} LcT;7yv  
wwv+s~(0  
L)8%*X  
//停止文件下载 8H1&=)M=  
public void siteStop() nBLb1T  
{ re,}}'  
bStop = true; aK_k'4YTm  
for(int i=0;i<nStartPos.length;i++) I2krxLPd  
fileSplitterFetch.splitterStop(); byTH SRt  
q&}+O  
VoQhzp6&  
} mN> (n+ly  
} JNT|h zV  
//负责部分文件的抓取 ;.<HpDfG_  
**FileSplitterFetch.java C9_[ke[1D  
*/ |Qb@.  
package NetFox; CMyz!jZ3  
Q5l+-  
]omBq<ox'Y  
import java.io.*; j<6+p r  
import java.net.*; )| |CU]"b?  
LM 1Vsh<  
U(Bmffn4Z  
public class FileSplitterFetch extends Thread { [>U2!4=$M  
:`lP+y?a1  
kem(U{m  
String sURL; //File URL B&BL<X r  
long nStartPos; //File Snippet Start Position FUZuS!sJ  
long nEndPos; //File Snippet End Position gX$gUB) x  
int nThreadID; //Thread's ID ,b5vnW\  
boolean bDownOver = false; //Downing is over gzy|K%K  
boolean bStop = false; //Stop identical Gm3`/!r  
FileAccessI fileAccessI = null; //File Access interface mB6%. "  
uHRxV"@}[1  
LPZ\T} <l  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g>#}(u!PH  
{ 1 .[OS  
this.sURL = sURL; Oqt{ uTI~  
this.nStartPos = nStart; .,U4 ATO  
this.nEndPos = nEnd; c4r9k-w0E  
nThreadID = id; U_.}V  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |/$954Hr#<  
} ori[[~OyB  
_ b</ ::Tp  
.6I'V3:Kg  
public void run() Eau V  
{ ITEf Q@#jU  
while(nStartPos < nEndPos && !bStop)  p: eaZ  
{ Y*O Bky  
CJw zjH  
(d* | |"  
try{ d2)]6)z6  
URL url = new URL(sURL); ?AQA>D#W  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Ssy (gt  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,H<nNBv 3M  
String sProperty = "bytes="+nStartPos+"-"; ue4 {h  
httpConnection.setRequestProperty("RANGE",sProperty); "`%UC#  
Utility.log(sProperty); g!r) yzK  
DRTT3;,N  
$!_}d  
InputStream input = httpConnection.getInputStream(); ~*+evAP  
//logResponseHead(httpConnection); AxF$7J(  
A:(qF.Tm  
fF=tT C  
byte[] b = new byte[1024]; p,uM)LD  
int nRead; 1CM 8P3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h|i b*%P_  
{ #`l&HV   
nStartPos += fileAccessI.write(b,0,nRead); 2+p XtP@O  
//if(nThreadID == 1) 4d}n0b\d  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hJw]hVYa  
} ~"4Cz27  
=<zlg~i  
-/*VR$c  
Utility.log("Thread " + nThreadID + " is over!"); "Vp:Sq9y  
bDownOver = true; =NnG[#n%  
//nPos = fileAccessI.write (b,0,nRead); :Z_abKt  
} $ 9E"{6;@  
catch(Exception e){e.printStackTrace ();} C7}iwklcsa  
} {a9.0N:4  
} z(2G"}  
<1:I[b  
5~(nHCf>  
//打印回应的头信息 $(08!U  
public void logResponseHead(HttpURLConnection con) 8YgRJQZ!  
{ ?P#\ CW  
for(int i=1;;i++) ; TwqZw[.  
{ F[F  NtZ  
String header=con.getHeaderFieldKey(i); H`Zg-j`  
if(header!=null) ~DB:/VSmu  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3/(eK%d4Xb  
Utility.log(header+" : "+con.getHeaderField(header)); jZvIqR/  
else 322-'S3<  
break; zzh7 "M3Qn  
} %\)AT"  
} ~XvMiWuo  
O`N,aYo  
f 9IqcCSW  
public void splitterStop() /rK/ l  
{ qF`]}7"^  
bStop = true; LcNI$g;}Yf  
} +Mn(s36f2  
02(Ob  
U7,.L  
} I?%#`Rvu  
fi&>;0?7  
+>c%I&h}`  
/* -7J~^m2x  
**FileAccess.java -$@'@U  
*//文件访问(定位,写) )oM% N  
package NetFox; <$#^)]Ts  
import java.io.*; 5>=4$!`  
pE0@m-p  
e ]2GAJLI  
public class FileAccessI implements Serializable{ y`/:E<fVk  
Eq8:[o  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XB:E<I'q!3  
RandomAccessFile oSavedFile; N f}ZG  
long nPos; NpbZt;%t  
ygK,t*T20  
Z]5xy_La  
public FileAccessI() throws IOException XXD4T9Wy  
{ ,Hp7`I>/  
this("",0); \`-xxhb?e  
} 4CS$%Cu\?w  
a'*~E ?b  
e. E$Ej]w  
public FileAccessI(String sName,long nPos) throws IOException P$@:T[}v  
{ 5B3sRF}  
oSavedFile = new RandomAccessFile(sName,"rw"); 5CH8;sMK  
this.nPos = nPos; xsvJjs;=  
oSavedFile.seek(nPos); {"rL3Lk  
} c s:E^  
>J:liB|(  
Mi}k>5VT  
public synchronized int write(byte[] b,int nStart,int nLen) bJ eF1LjS  
{ KsqS{VVCh  
int n = -1; ItZ*$I1<  
try{ k? ,/om1  
oSavedFile.write(b,nStart,nLen); s>{\^T7y  
n = nLen; F9r|EU#;  
} )L_@l5l  
catch(IOException e) !|mzu1S  
{ PM QlJ&  
e.printStackTrace (); e Dpt1  
} { / ,?3  
ITz+O=I4R]  
{Z>Mnw"R  
return n; %P C[-(Q  
} `@So6%3Y|  
"DX 2Mu=  
m;U_oxb  
} P\@efq@!  
8RS@YO  
 7b8y  
/* 8}Q 2!,9Q  
**SiteInfoBean.java FU)=+m  
*/ I:;umyRH  
package NetFox; *-E'$  
3A.lS+P1  
m+x$LkP  
public class SiteInfoBean { Sj v iH  
p]7IoO -@  
R^INl@(O  
private String sSiteURL; //Site's URL 0aJcX)  
private String sFilePath; //Saved File's Path f`[E^ zj  
private String sFileName; //Saved File's Name _auFt"n  
private int nSplitter; //Count of Splited Downloading File h" f_T [  
1=PTiDMJ<*  
&#!1 Y[e^  
public SiteInfoBean() #1WCSLvtV  
{//nSplitter的缺省值为5 qTG i9OP6/  
//default value of nSplitter is 5 YhP+{Y8t  
this("","","",5); q RRvZhf  
} b&9~F6aM  
a.a ,_  
xrv0%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VL|Z+3L  
{ mri g5{  
sSiteURL= sURL; jVqpokWH  
sFilePath = sPath; +fQJ#?N2n  
sFileName = sName; \p^'[B(O77  
this.nSplitter = nSpiltter; FB %-$  
B`)bo}h  
dk0} q6~  
} 2q*wYuc  
fm!\**Q1  
b Rr3:"=sE  
public String getSSiteURL() `A-  
{ Y8N+v+V/  
return sSiteURL; sD|}? 7  
} NCgKWyRR  
TIK'A<  
*U`R<mV\  
public void setSSiteURL(String value) )_6W@s  
{ Kq(JHB+  
sSiteURL = value; ex66GJQe1  
} FrE#l.)?!  
8\jsGN.$JZ  
o'8nQ Tao  
public String getSFilePath() D  ,[yx='  
{ LjIkZ'HuF  
return sFilePath; T`9nY!  
} kdaq_O:s  
Zay%QNsb  
Z;njSw%:  
public void setSFilePath(String value) 9!.S9[[N  
{ 0%)T]SDS  
sFilePath = value; ~YByyJG   
} E()%IC/R  
^]Z@H/]H  
&(e5*Q  
public String getSFileName() C~C`K%7  
{ lQy-&d|=#^  
return sFileName; ) $0>L5d:  
} !Uv>>MCr  
|dDKO  
=^\?{oV  
public void setSFileName(String value) f>|<5zm#<  
{ H!>>|6OPF  
sFileName = value; 6YV"H  
} 5"X@<;H%  
{R_ <m$  
z7+>G/o  
public int getNSplitter() )PW|RW  
{ IW-|"5?9'  
return nSplitter; Kr;=4xg=  
} |o'r?"  
L27WDm^)  
$?dQ^]<,  
public void setNSplitter(int nCount) UtQCTNjC{  
{ IAmZ_2  
nSplitter = nCount; _O ;4>  
} upX@8WxR  
} o\; hF3   
dZI["FeO&d  
YBR)S_C$_  
/* Ob}XeN(L3  
**Utility.java +S`cUn7  
*/ ),[@NK&=  
package NetFox; \CV HtV  
(E,Ibz2G:e  
adAdX;@e`  
public class Utility { pLys%1hg  
vU]n0)<KB  
Nh}u]<B  
public Utility() h+A+>kC5  
{ !2^~ar{2  
&Yc'X+'4  
=LKM)d=1  
} +l.LwA  
Pai8r%Zfu  
//线程睡眠 #S x  
public static void sleep(int nSecond) O:GAS [O`  
{ V|[NL4  
try{ [HUK 9hG  
Thread.sleep(nSecond); xSNGf@1b  
} 3,X8 5`v^  
catch(Exception e) qxsHhyB_n;  
{ x5V))~Ou  
e.printStackTrace (); VJFFH\!`  
} ?Zsh\^k.g  
} R!lug;u#  
nc\2A>f`  
//日志 aM(#J7;  
public static void log(String sMsg) R/*"N'nH-%  
{ I%GQ3D"=  
System.err.println(sMsg); TA2ETvz^  
} pek=!nZ  
 OK8Ho"  
RyG6_ G}  
public static void log(int sMsg) O`"~AY&  
{ YD;d*E%t  
System.err.println(sMsg); iyd$_CJz  
} X!mJUDzh]  
} LHXR7Fjc  
VJT /9O)Z|  
Xt$P!~Lu  
/* 4Orq;8!BW  
**TestMethod.java x[Hx.G}5+  
*/ TI/RJF b  
package NetFox; o3GkTn O  
6M_:D  
5J|S6x\  
public class TestMethod { P=KhR&gwV~  
~cfXEjE6  
D7JrGaF{  
public TestMethod() jZPGUoRLg  
{ ///xx/weblogic60b2_win.exe i*m ;kWu,  
try{ ~:o$}`mW  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wy tMoG\  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I`rN+c:  
SiteFileFetch fileFetch = new SiteFileFetch(bean); cNxxX!P/  
fileFetch.start(); 6 U[VoUU   
} {*TB }Xsr,  
catch(Exception e){e.printStackTrace ();} r|DIf28MIq  
9d-'%Q>+  
+xO3<u  
} fCF.P"{W"  
E;x-O)(&  
3nc\6v%  
public static void main(String[] args) v<g=uEpN  
{ KsE$^`  
new TestMethod(); B5vLV@>]  
} o:W*#dt  
} f$kbb 6juL  
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