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http断点续传简单实现(java)

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/* xL9:4'I  
**SiteFileFetch.java PYdIP\<V  
*/ ?"()>PJx  
package NetFox; {F;,7Kn+l  
import java.io.*; X}3P1.n:  
import java.net.*; ]WTf< W<  
]O6KKz  
^ H'hD  
public class SiteFileFetch extends Thread { J9g|#1G  
/yLzDCKn  
w@87]/4Rq  
SiteInfoBean siteInfoBean = null; //文件信息Bean _aVJ$N.  
long[] nStartPos; //开始位置 oR-O~_) U  
long[] nEndPos; //结束位置 /0Z|+L9Jo  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N YCj; ,V  
long nFileLength; //文件长度 5){tBK|  
boolean bFirst = true; //是否第一次取文件 zx ct(  
boolean bStop = false; //停止标志 X7e>Z)l  
File tmpFile; //文件下载的临时信息 qIB>6bv#x  
DataOutputStream output; //输出到文件的输出流 6kP7   
Q}WL/X5  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9 TqoLX  
public SiteFileFetch(SiteInfoBean bean) throws IOException +#0~:&!9  
{ u@AI&[Z  
siteInfoBean = bean; pI  &o?n  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Bk&-1>cY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Xwn3+tSIa  
if(tmpFile.exists ()) !A~d[</]m  
{ F;pTXt}?5  
bFirst = false; cN62M=**  
read_nPos(); ^gd<lo g  
} Po1hq2-U8  
else aPprMQ5  
{ tJff+n>  
nStartPos = new long[bean.getNSplitter()]; I%SuT7"Do  
nEndPos = new long[bean.getNSplitter()]; I4rV5;f H4  
} ojX%RU  
l+t #"3  
;?0_Q3IML  
UMT\Q6p  
} k}X[u8A  
xM% pvx.'L  
I"B8_  
public void run() f(!E!\&n^  
{ ,g%o  
//获得文件长度 w- r_H!-  
//分割文件 Ft3I>=f{  
//实例FileSplitterFetch y7>iz6N  
//启动FileSplitterFetch线程 8B j4 _!g  
//等待子线程返回 nHnk#SAA u  
try{ xsYE=^uv  
if(bFirst) t @;WgIp(&  
{ 7LG+$LEz  
nFileLength = getFileSize(); ZOp^`c9~  
if(nFileLength == -1) oL#xDG  
{ ]+mjOks~  
System.err.println("File Length is not known!"); 3u*82s\8T  
} WPtMds4  
else if(nFileLength == -2) J`W-]3S#  
{ 8}bZ [  
System.err.println("File is not access!");  -H`\? R  
} ]\7lbLv  
else X R4)z  
{ [$^A@bqk  
for(int i=0;i<nStartPos.length;i++) s\_l=v3  
{ `{DG;J03[  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6nc0=~='$  
} FW_G\W.  
for(int i=0;i<nEndPos.length-1;i++) z9 O~W5-U  
{  O)OUy  
nEndPos = nStartPos[i+1]; }~rcrm.   
} /oFc 03d  
nEndPos[nEndPos.length-1] = nFileLength; B "*`R!y  
} `v~!H\q  
} 0D<TF>M;pn  
cI3y  
7^Na9]PY  
//启动子线程 ?d4Boe0-a2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NIaF5z  
for(int i=0;i<nStartPos.length;i++) YwGH G{?e  
{ ^xt9pa$f  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TMqY4;UeL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ALfiR(!  
nStartPos,nEndPos,i); 3^XVQS***  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ka#K [qI  
fileSplitterFetch.start(); t}VwVf<K  
} 6%E~p0)i%  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :\ mRtVH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k}HQq_Y(<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vu<#wW*9  
nEndPos = " + nFileLength); _|X7 n~  
// fileSplitterFetch[nPos.length-1].start(); n08; <  
;Xyte  
BB63x Ex  
//等待子线程结束 .9OFryo  
//int count = 0; IfMpY;ow=  
//是否结束while循环 +1/b^Ac  
boolean breakWhile = false; +qhnP$vIe  
JD ]OIh  
1Fs-0)s8  
while(!bStop) 0vn[a,W<A  
{ p0Gk j-  
write_nPos(); +RS$5NLH  
Utility.sleep(500); F?cq'd  
breakWhile = true; 5/ * >v  
VRF6g|0;  
L%XXf3;c  
for(int i=0;i<nStartPos.length;i++) ` 5#h jLe  
{ ab@=cL~^  
if(!fileSplitterFetch.bDownOver) {OCJ(^8i  
{ qU-!7=}7  
breakWhile = false; (UGol[f<  
break; 1Cv#nhmp  
} 84^[/d;!  
} E M Q4yK  
if(breakWhile) ZE rdt:w  
break; CU$)QH{  
e #M iaX  
+I@cO&CY|  
//count++; iDw.i"b  
//if(count>4) &\^rQi/tf  
// siteStop(); U-g9C.  
} Xu6K%]i^  
036[96t,F  
3cixQzb}u  
System.err.println("文件下载结束!"); (sCAR=5v\  
} I+" lrU  
catch(Exception e){e.printStackTrace ();} Yb 6q))Y  
} /zT`Y=1  
6G}c1nWU  
h55>{)(E  
//获得文件长度 MwAJ(  
public long getFileSize() 8teJ*sz  
{ .YR8v1Cp  
int nFileLength = -1; 'I v_mig  
try{ 6,+nRiZ  
URL url = new URL(siteInfoBean.getSSiteURL()); B |&F%P0:  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #tDW!Xv?  
httpConnection.setRequestProperty("User-Agent","NetFox"); Y)Tl<  
Kt6>L5:94  
c`jDW S  
int responseCode=httpConnection.getResponseCode(); % O%xpSYr  
if(responseCode>=400) PS@*qTin  
{ Ri @`a  
processErrorCode(responseCode); 1 i3k  
return -2; //-2 represent access is error NR3`M?Hjf  
} k':s =IXW  
>f$NzJ}  
vq>l>as9O  
String sHeader; b\giJ1NJB  
;LQ9#M?  
CGZ^hoh/  
for(int i=1;;i++) opD-vDa h  
{ bX2"89{  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L/i(KF{  
//Utility.log(in.readLine()); ARWZ; GX  
sHeader=httpConnection.getHeaderFieldKey(i); v{y{sA  
if(sHeader!=null) J(s;$PG  
{ {G*OR,HN  
if(sHeader.equals("Content-Length")) h1f8ktF  
{ QDE$E.a  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7&+Ys  
break; @G*.1;jO  
} 5I' d PNf  
} QVtM.oi!Q  
else " U8S81'  
break; ^npJUa  
} 1'O0`Me>#  
} Im)EDTm$  
catch(IOException e){e.printStackTrace ();}  zF: j  
catch(Exception e){e.printStackTrace ();} Uu'dv#4Iw  
<3Gqv9Y&  
:=fvZAWD  
Utility.log(nFileLength); iM5vrz`n  
hs(W;tR@W  
;LMWNy4  
return nFileLength; Wi$dZOcSJ  
} FjFwvO_.  
.Dw,"VHP  
~xDw*AC-  
//保存下载信息(文件指针位置) c-8!#~M(  
private void write_nPos() z<&m*0WYA  
{ wC` R>)  
try{ 1mH\k5xu  
output = new DataOutputStream(new FileOutputStream(tmpFile)); SlaDt  
output.writeInt(nStartPos.length); zOB=aG?/  
for(int i=0;i<nStartPos.length;i++) A'-_TFwW  
{ Ik~1:D]f  
// output.writeLong(nPos); Fn+ ?u  
output.writeLong(fileSplitterFetch.nStartPos); op@i GC+  
output.writeLong(fileSplitterFetch.nEndPos); &leK}je [  
} ,}J_:\j  
output.close(); 50n}my'2h  
} F]_cbM{8/  
catch(IOException e){e.printStackTrace ();} a$JLc a  
catch(Exception e){e.printStackTrace ();} \ZH&LPAY  
} XvKFPr0~  
GwLFL.Ke  
xs!p|  
//读取保存的下载信息(文件指针位置) JhX=l-?  
private void read_nPos() ir[jCea,  
{ hfrnxeM#~  
try{ Uyx&E?SlEq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =yXs?y"  
int nCount = input.readInt(); ;t(f1rPyE  
nStartPos = new long[nCount]; qf8[!5GM  
nEndPos = new long[nCount]; S$[k Q|Am  
for(int i=0;i<nStartPos.length;i++) 0rE(p2  
{ NlF}{   
nStartPos = input.readLong(); 'q{733o  
nEndPos = input.readLong(); Vrp[r *V@E  
} 'C>U=cE7  
input.close(); ]R IVc3?;$  
} -]S.<8<$  
catch(IOException e){e.printStackTrace ();} \Fb| {6+  
catch(Exception e){e.printStackTrace ();} Qe$k3!  
} jH *)%n5,\  
Q8qz*v]{  
=Ho"N`Qy  
private void processErrorCode(int nErrorCode) lMifpK  
{ h(' )"  
System.err.println("Error Code : " + nErrorCode); t"AzI8O  
} } !s!;BOx  
ycr"Y|  
Wa'sZ#  
//停止文件下载 0 f/.>1M=  
public void siteStop() %2l7Hmp4H  
{ uT_!'l$fr  
bStop = true; !#x=JX  
for(int i=0;i<nStartPos.length;i++) ;#k-)m%  
fileSplitterFetch.splitterStop(); q/gB<p9  
G/?~\ }:s  
R,_d1^|*w  
} >e&:`2%.  
} SO?8%s(   
//负责部分文件的抓取 BNucc']  
**FileSplitterFetch.java %NARyz  
*/ Qt+:4{He  
package NetFox; z/]q)`G  
<7sIm^N  
K_BPZ5w  
import java.io.*; .tXtcf/  
import java.net.*; {}Ejt:rKN  
yTBS=+X  
2eP ;[o  
public class FileSplitterFetch extends Thread { TprtE.mP  
d"Q |I  
$2#7D* Rx  
String sURL; //File URL NPjv)TN}3  
long nStartPos; //File Snippet Start Position SUtf[6  
long nEndPos; //File Snippet End Position 0$vj!-Mb^j  
int nThreadID; //Thread's ID E~hzh /,34  
boolean bDownOver = false; //Downing is over 6oL1_)  
boolean bStop = false; //Stop identical Mi7y&~,  
FileAccessI fileAccessI = null; //File Access interface #D%ygh=  
*cv}*D  
u{f* M,k  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )Y]/^1hx  
{ 5#JJ?  
this.sURL = sURL; Q<"[C 1Lj  
this.nStartPos = nStart; CAc %f9!3  
this.nEndPos = nEnd; eE]hy'{d<  
nThreadID = id; ,?-\ x6  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &#m"/g7w4N  
} !~iGu\y  
vS?odqi#n  
IB5BO7J  
public void run() ;N=G=X|}  
{ Ug"rJMZG  
while(nStartPos < nEndPos && !bStop) SZ!=`a]  
{ [`_io>*g  
cma*Dc  
-$a>f4]  
try{ XhW %,/<  
URL url = new URL(sURL); M8;lLcgu.  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eE8ULtO  
httpConnection.setRequestProperty("User-Agent","NetFox"); )g1a'G  
String sProperty = "bytes="+nStartPos+"-"; 3Rv7Qx  
httpConnection.setRequestProperty("RANGE",sProperty); x4K`]Fvhl  
Utility.log(sProperty); <:;^'x>!  
hfM;/  
nBLj [  
InputStream input = httpConnection.getInputStream(); h{iEZ#  
//logResponseHead(httpConnection); ,/Cq v   
WE!vSZ3R  
'c`jyn  
byte[] b = new byte[1024]; vK'?:}~  
int nRead; LXfCmc9|Z  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5\4g>5PD  
{ L/r@ S'  
nStartPos += fileAccessI.write(b,0,nRead); m:CTPzAt  
//if(nThreadID == 1) \E4B&!m  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~Gv#iRi>  
} \NL+}cL/  
b=PVIZ  
3sm M,fi  
Utility.log("Thread " + nThreadID + " is over!"); ": ;@Hnb/  
bDownOver = true; i6PM<X,{;  
//nPos = fileAccessI.write (b,0,nRead); '/%zi,0  
} UVu DQ  
catch(Exception e){e.printStackTrace ();} )mcEQ-!b  
} $ 17 su')  
} JhK/']R  
X]*QUV]i  
|;vi*u  
//打印回应的头信息 oR#:Nt X@  
public void logResponseHead(HttpURLConnection con) '\DSTr:N  
{ HeN~c<NuB  
for(int i=1;;i++) v90T{1+M|4  
{ &<x@1,  
String header=con.getHeaderFieldKey(i); Ukphd$3J=  
if(header!=null) qN| fEO>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VHUW]8We  
Utility.log(header+" : "+con.getHeaderField(header)); Z@rN_WXx  
else &XLD S=j  
break; ?w&SW{ I  
} /X8 <C=}  
} 7,$z;Lr0S  
|QZ 58)>  
' P"g\;Ij  
public void splitterStop() [IBQvL  
{ aw $L$7b}  
bStop = true; %:C ]7gQ  
} r64u31.)  
TCVl8)j  
E@)\Lc~  
} n-;y*kD  
9h,u6e  
>`T5]_a  
/* p='-\M74K  
**FileAccess.java deX5yrvOie  
*//文件访问(定位,写) )h$NS2B`  
package NetFox; wo^Sy41bF  
import java.io.*; (&\aA 0-}H  
;e8V +h  
_!V%fw  
public class FileAccessI implements Serializable{ ^U7OMl4Usq  
rnm03 '{  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LJzH"K[Gg6  
RandomAccessFile oSavedFile; R!x: C!{  
long nPos; 7 6fIC  
L#h:*U{@40  
vR7HF*8  
public FileAccessI() throws IOException B/uniR^x  
{ w Fn[9_`*  
this("",0); l95<QI  
} &~sfYW  
tx7~S Ur  
V`hu,Y;%  
public FileAccessI(String sName,long nPos) throws IOException e_3CSx8Cc  
{ xl4=++pu)  
oSavedFile = new RandomAccessFile(sName,"rw"); QP I+y8N=  
this.nPos = nPos; ctmQWrk|B  
oSavedFile.seek(nPos); u62)QJE  
} -#&kYK#Ph  
,t$,idcT+  
bMoAD.}  
public synchronized int write(byte[] b,int nStart,int nLen) d}I (`%%)  
{ #&!G"x7  
int n = -1; ,2[ra9n  
try{ M~T.n)x2  
oSavedFile.write(b,nStart,nLen); D vkxI<Xa  
n = nLen; TQ :/RT  
} d4^`}6@  
catch(IOException e) Tp%(I"H'_;  
{ pa .K-e)Mu  
e.printStackTrace (); sYbH|}  
} ?h\mk0[  
}k$4/7ri  
wOgE|n  
return n; S9sR#  
} OJ>.-"  
Bn wzcl  
ik1tidw  
} n(Y%Vmy  
rx ~[Zs+*  
5t:8.%<UK  
/* <!^ [~`  
**SiteInfoBean.java LwJ0  
*/ Ps[$.h  
package NetFox; eH>#6R1-  
"AueLl)  
%uESrc-;  
public class SiteInfoBean { *e.*=$  
;]D(33) (  
H6kf K5,  
private String sSiteURL; //Site's URL D}mL7d1  
private String sFilePath; //Saved File's Path &wH:aD  
private String sFileName; //Saved File's Name QOFvsJ<s  
private int nSplitter; //Count of Splited Downloading File H:&?ha,9  
>O`l8tM  
eBW=^B"y+  
public SiteInfoBean() %B2XznZ:  
{//nSplitter的缺省值为5 P!g-X%ngo  
//default value of nSplitter is 5 X~T/qFS   
this("","","",5); C"<s/h  
} TvhJVVQ+?  
my\&hCE  
Iq5pAHm>M6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b}z`BRCc  
{ 6Y*;{\Rd  
sSiteURL= sURL; RNJ FSD.  
sFilePath = sPath; Va<H U:<  
sFileName = sName; jRZ%}KX  
this.nSplitter = nSpiltter; 0NE{8O0;Fr  
~9o6 W",  
|WQ9a' '  
} O_,O,1  
U..<iNQE5  
[IX+M#mf  
public String getSSiteURL() f_mhD dq  
{ .QWhK|(.!  
return sSiteURL; =jAFgwP\  
} lP<I|O=z  
6 DF  
Rs;15@t@  
public void setSSiteURL(String value) -e-e9uP  
{ E0f{iO;}  
sSiteURL = value; ?r_kyuU  
} fZryG  
:J_oj:0r"f  
Csst[3V  
public String getSFilePath() S\C*iGeqJ  
{ _kraMQ>  
return sFilePath; "PWl4a&  
} nS.G~c|  
/MTf0^9  
Fe=8O ^\  
public void setSFilePath(String value) 9M$/=>^ Z  
{ @s* ,xHE  
sFilePath = value; 3}Xc71|v  
} Mhpdaos  
/Bv#) -5  
y.a]r7  
public String getSFileName() 5N/Lk>p1u  
{ |Ur"za;%@  
return sFileName; >9K//co"of  
} n]? WCG}cd  
S q@H  
w<nv!e?  
public void setSFileName(String value) kyUl{Zj  
{ gSi5u# }J  
sFileName = value; HMQI&Lh=U  
} ZW4aY}~)$  
mf$j03tu  
UsW5d]i}Y  
public int getNSplitter() t 0O4GcAN  
{ f?UzD#50D  
return nSplitter; L10IF  
} %_)zWlN  
|"7Pv skT  
7!4V >O8@  
public void setNSplitter(int nCount) >.%4~\U  
{ Epjff@ 7A  
nSplitter = nCount; @PkJY  
} E%pz9gcSx  
} H oy7RC&  
RIy\u >  
r|Zi3+  
/* ]r"Yqv3  
**Utility.java Zr/r2  
*/ gQVBA %  
package NetFox; yY=<'{!  
a5c'V   
;Rnhe_A.  
public class Utility { QApyP CH  
BSUPS+@+  
.XH8YT42  
public Utility() \_ow9vU  
{ f6ZZ}lwaV  
,@CfVQz  
4('JwZw\!  
} 8C&x MA^  
9C}qVoNu  
//线程睡眠 {U @3yB  
public static void sleep(int nSecond)  &"S/Lt  
{ +<(a}6dt  
try{ &^QPkX@p  
Thread.sleep(nSecond); AlX3Wv }  
} :=!Mh}i  
catch(Exception e) y?:dE.5p|  
{ YMzBAf  
e.printStackTrace (); Go8F5a@j  
} BQrL7y  
} F @SG((`  
*@M3p}',M  
//日志 %J P!{mqj  
public static void log(String sMsg) Da,Tav%b  
{ 8 njuDl  
System.err.println(sMsg); X#J6Umutm  
} \lr/;-zP  
(cV  
rw u3Nb  
public static void log(int sMsg) *o4%ul\3Y|  
{ A~71i&  
System.err.println(sMsg); {BOLP E-  
}  rz  
} &?<AwtNN  
_Z#eS/,O@  
~"7J}[i 5  
/* fPQ|e"?  
**TestMethod.java F=Y S^  
*/ )/Y~6A9>  
package NetFox; f%Ke8'&  
UxqWnHH.`  
Q1V2pP+=@  
public class TestMethod { 5 si}i'in  
7'.s7& '7  
%C *^:\y  
public TestMethod() qei$<j'b  
{ ///xx/weblogic60b2_win.exe }98-5'u.X  
try{ SMO*({/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .ZX2^)`XD  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G11cNr>*  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3M*Y= ?pI  
fileFetch.start(); [j0w\{  
} JMsHK,(  
catch(Exception e){e.printStackTrace ();} %zljH"F  
n7iE8SK|k  
{nRUH*(d9  
} I'A:J  
eP|)SU  
,)$Wm-  
public static void main(String[] args) >d%VDjk .  
{ Gpu_=9vzv  
new TestMethod(); _Ex?Xk  
} ] 09yy  
} DTy/jaK  
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