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http断点续传简单实现(java)

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/* S]9:3~  
**SiteFileFetch.java :I F&W=?9  
*/ Gc4N)oq)}b  
package NetFox; =@binTC4  
import java.io.*; sG0cN;I]t  
import java.net.*; 9 o-T#~i  
H4KwbTT"+  
E[nWB"pxE  
public class SiteFileFetch extends Thread { =9YyUAJZ  
^gH.5L0]gH  
phl5E:fIKx  
SiteInfoBean siteInfoBean = null; //文件信息Bean (bH"x  
long[] nStartPos; //开始位置 2j4VW0:  
long[] nEndPos; //结束位置 X||o iqbY  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {;Mcor3  
long nFileLength; //文件长度 .+ai dWd  
boolean bFirst = true; //是否第一次取文件 1 < <`T%&  
boolean bStop = false; //停止标志 /Rx%}~x/m  
File tmpFile; //文件下载的临时信息 cpFw]w%]  
DataOutputStream output; //输出到文件的输出流 kdQ=%  
- CT?JB  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) o,D>7|h  
public SiteFileFetch(SiteInfoBean bean) throws IOException {^"c>'R  
{ 0OEyJ|g  
siteInfoBean = bean; )`-9WCd&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); A7+eWg{  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); r&1N8o  
if(tmpFile.exists ()) e@Z(z^V  
{ 6N~~:Gt  
bFirst = false; yXppu[=  
read_nPos(); U&wVe$  
} %=S^{A  
else rA8neO)  
{ = Yh>5A  
nStartPos = new long[bean.getNSplitter()]; ^z9ITGB~tV  
nEndPos = new long[bean.getNSplitter()]; m {_\@'q  
} vay_QxB5  
(IIOKx_  
d|j3E  
26 o68U8&y  
} 8Th|'  
A37Z;/H~k  
D>?%p"e  
public void run() lp!@uoN^T  
{ kIrME:  
//获得文件长度 ut& RKr3  
//分割文件 +S^Uw'L$=T  
//实例FileSplitterFetch zg)Z2?K|;u  
//启动FileSplitterFetch线程 t \DS}3pv  
//等待子线程返回 V2i*PK X  
try{ U,[vfSDGr  
if(bFirst) rbO9NRg>  
{ 9"=:\PE  
nFileLength = getFileSize(); B\KvKT|\  
if(nFileLength == -1) , YTuZS  
{ `Kpn@Xg  
System.err.println("File Length is not known!"); o`M7:8G  
} Xy_+L_h^  
else if(nFileLength == -2) Z7K ;~*  
{  #XQEfa  
System.err.println("File is not access!"); C[&  \Xq  
} ,hT t]w  
else KNQX\-=  
{ b0 PF7PEEQ  
for(int i=0;i<nStartPos.length;i++) QI=",vma u  
{ SD8Q_[rY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); V. =!^0'A  
} BNQ~O^R0  
for(int i=0;i<nEndPos.length-1;i++) &=<x&4H+  
{ :f 1*-y  
nEndPos = nStartPos[i+1]; IObGmc  
} QC \8Zy  
nEndPos[nEndPos.length-1] = nFileLength; !RFlv  
} ,K+K`"Oy  
} 8nt:peJ$+  
3"6lPUS  
X*]uLgbl  
//启动子线程 ,Tvk&<!0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \n6#D7OV  
for(int i=0;i<nStartPos.length;i++) TW{.qed8^  
{ BV9B}IV  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \P^WUWY  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eqZ V/a  
nStartPos,nEndPos,i); :nC Gqg  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xl5mI~n_~  
fileSplitterFetch.start(); +]Po!bN@@  
} ht!o_0{~  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a+uSCs[C  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ",w@_}z:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^UEI`_HO0  
nEndPos = " + nFileLength); t}c ymX~  
// fileSplitterFetch[nPos.length-1].start(); BCJo/m  
fp.,MIS  
rNO'0Ck=  
//等待子线程结束 V~+Oil6sa  
//int count = 0; Q\<C9%a  
//是否结束while循环 ,gUSW  
boolean breakWhile = false; &UEr4RK;I  
g"`BNI]Qp  
$!G7u<`na  
while(!bStop) i`z1if6O  
{ ?y>P  
write_nPos(); vYKKv%LE  
Utility.sleep(500); Urm&4&y  
breakWhile = true; [v^T]L  
CJz2.yd  
=!GUQLS{  
for(int i=0;i<nStartPos.length;i++) K;k_MA310  
{ /$|C s  
if(!fileSplitterFetch.bDownOver) 4;<?ec(dc  
{ W.r0W2))(  
breakWhile = false; <ZSH1~<{6  
break; V\W?@V9g-  
} x{*g^f  
} kl?U 2A.=  
if(breakWhile) re2M!m6k5  
break; 4`I2tr  
FDbb/6ku  
fFMGpibkM  
//count++; -Ds}kdxw  
//if(count>4) ['~3"lK^O  
// siteStop(); }TzMWdT  
} .__XOd} K  
@i'RIL}  
)D{L<.i_  
System.err.println("文件下载结束!"); b^~ keQ  
} A5S9F8Q/]  
catch(Exception e){e.printStackTrace ();} 1p[C5j3  
} 64%P}On  
` .|JTm[  
[a:yKJ[  
//获得文件长度 ,|D_? D)U  
public long getFileSize() 5Ev9u),D+v  
{ ]JVs/  
int nFileLength = -1; t3|If@T  
try{ k@L},Td  
URL url = new URL(siteInfoBean.getSSiteURL()); ~Z9Eb|B  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lr'h  
httpConnection.setRequestProperty("User-Agent","NetFox"); !8lG"l|,l  
"1FPe63\*O  
DzydS=`w  
int responseCode=httpConnection.getResponseCode(); |`+kZ-M*  
if(responseCode>=400) ]v(8i3P84  
{ Jz&a9  
processErrorCode(responseCode); Cc/h|4  
return -2; //-2 represent access is error ,m;S-Im_Xr  
} Jr$,w7tQn@  
ELfcZfJ  
tJ>%Xop  
String sHeader; L.ScC  
]VtVw^ir  
%X7R_>.   
for(int i=1;;i++) Y~gDS^8  
{ d[E~}Dq3#  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N[~{'i  
//Utility.log(in.readLine()); Xb?:dlu3  
sHeader=httpConnection.getHeaderFieldKey(i); {; #u~e(W  
if(sHeader!=null) H=Scrvfx  
{ }{T9`^V:h  
if(sHeader.equals("Content-Length")) )hs"P%Zg  
{ ;\ ^'}S|3Z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dk8 O*B   
break; eG&\b-%  
} d3-F?i 5d  
} 2l]*><q|  
else t5t,(^;f  
break; 3*)<Y}Tc  
} w^OV;gp  
} R[KF${X4  
catch(IOException e){e.printStackTrace ();} zmH8^:-x  
catch(Exception e){e.printStackTrace ();} jBZlN Ew  
QZ?#ixvJ  
 ;wo  
Utility.log(nFileLength); > %h7)}U  
% `Q[?(z  
}<R,)ZV^G  
return nFileLength; iO1ir+B\  
} Z6s-n$dSm  
w0qrh\3du  
`EKmp|B_p_  
//保存下载信息(文件指针位置) ~puXZCatN  
private void write_nPos() b3R1L|@  
{ 7k,pUC-w7c  
try{ ,;;7+|`  
output = new DataOutputStream(new FileOutputStream(tmpFile)); NwAvxN<R(f  
output.writeInt(nStartPos.length); <;Q1u,Mc  
for(int i=0;i<nStartPos.length;i++) @Wgd(Ezd  
{ DJ_[{WAV  
// output.writeLong(nPos); wcr3ugvT  
output.writeLong(fileSplitterFetch.nStartPos); s%M#  
output.writeLong(fileSplitterFetch.nEndPos); eS#kDa/ %  
} 5Ku=Xzvq  
output.close(); x }\x3U  
} O[}{$NXw  
catch(IOException e){e.printStackTrace ();} {1?94rz  
catch(Exception e){e.printStackTrace ();} U*sjv6*T  
} LGnb"ZN  
)/HbmtXqI  
KLb"_1z  
//读取保存的下载信息(文件指针位置) [|iWLPO1&k  
private void read_nPos() +85#`{ D  
{ y7CC5S ?  
try{ 5k:SD7^b  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o\/&05rp]  
int nCount = input.readInt();  NOY`1i  
nStartPos = new long[nCount]; k=]#)A(#C  
nEndPos = new long[nCount]; {!RDb'Zp  
for(int i=0;i<nStartPos.length;i++) f3yH4r?;w  
{ U ?iw  
nStartPos = input.readLong(); %MG{KG=&o  
nEndPos = input.readLong(); E_q/*}]pE  
} L hp  
input.close(); jej.!f:H  
} ~[8n+p+&X  
catch(IOException e){e.printStackTrace ();} rR Kbs@1M  
catch(Exception e){e.printStackTrace ();} q+iG:B/Z  
} %G0J]QY{(x  
4X-"yQ<U  
CdBpz/  
private void processErrorCode(int nErrorCode) Vz.G!*>Dg  
{ _V2^0CZ  
System.err.println("Error Code : " + nErrorCode); Eep~3U  
} %x'}aTa  
m:}PVJ-"  
7eNLs  
//停止文件下载 mM9aT0_w  
public void siteStop() \;XDPC j  
{ VSx9aVPkC  
bStop = true; [T |P|\M  
for(int i=0;i<nStartPos.length;i++) N5PW]  
fileSplitterFetch.splitterStop(); J#.f%VJ  
Ky0}phGRu  
2xLEB&  
} ^VC /tJ  
} # &,W x  
//负责部分文件的抓取 }Q2v~eD  
**FileSplitterFetch.java 7xF)\um  
*/ ]?< wUd  
package NetFox; U g:  
*S xDwN  
awXK9}.  
import java.io.*; FR9w0{o  
import java.net.*; HNJR&U t  
RWg'W,v=!  
/^]/ iTg  
public class FileSplitterFetch extends Thread { Z";&1cK  
` 0$i^,}  
zqHG2:MN"  
String sURL; //File URL OV G|WC  
long nStartPos; //File Snippet Start Position ^4b;rLfk@  
long nEndPos; //File Snippet End Position Iuyq!R4:7  
int nThreadID; //Thread's ID ZUyS+60  
boolean bDownOver = false; //Downing is over m?< ^b_a}  
boolean bStop = false; //Stop identical ~8 B]  
FileAccessI fileAccessI = null; //File Access interface f+ cN'jH E  
 -uKTEG[  
Ypx5:gm|J  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]'NL-8x">  
{ nt&"? /s  
this.sURL = sURL; 57fl<IM  
this.nStartPos = nStart; 4wMZNa<Sx  
this.nEndPos = nEnd; y Nc@K|  
nThreadID = id; jn 5v  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aD(3.=[R  
} t$Bu<frQ  
q+znb'i-x  
8J#U=qYei  
public void run() /[=Yv!  
{ ZaBmH|k  
while(nStartPos < nEndPos && !bStop) qzj.N$9]  
{ +v2)'?BS  
^w!1QH0:/  
HA J[Y3d<  
try{ sYq:2Wn>8Q  
URL url = new URL(sURL); yV~TfTJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A`--*$8\  
httpConnection.setRequestProperty("User-Agent","NetFox"); +CVB[r#hu  
String sProperty = "bytes="+nStartPos+"-"; M }! qH.W  
httpConnection.setRequestProperty("RANGE",sProperty); Z0/$XS9|h;  
Utility.log(sProperty); |KR8=-!7  
fsl ZJE  
~.tl7wKkR/  
InputStream input = httpConnection.getInputStream(); \.aKxj5  
//logResponseHead(httpConnection); 0HO'%'Ga*  
csd9[=HW/Q  
x8xz33  
byte[] b = new byte[1024]; <NEz{1Z  
int nRead; =@nE:uto]  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5DpvMhc_  
{ J-|&[-Z  
nStartPos += fileAccessI.write(b,0,nRead); 4@+']vN4  
//if(nThreadID == 1) Q>q-6/|UX  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R XCjYzt  
} ?I8r2M]  
A<] $[2qPj  
74 W Ky  
Utility.log("Thread " + nThreadID + " is over!"); }rvX}   
bDownOver = true; gg/ts]$  
//nPos = fileAccessI.write (b,0,nRead); V'tqsKQ!  
} EKD#s,(V*X  
catch(Exception e){e.printStackTrace ();} !F:mD ZeY  
} A^E 6)A=  
} r#A*{4wz  
m68>`  
B^!-%_q  
//打印回应的头信息 -e_|^T"  
public void logResponseHead(HttpURLConnection con) ]h#QA;   
{ id588Y78  
for(int i=1;;i++) fP[S.7F+No  
{ '`YZJ  
String header=con.getHeaderFieldKey(i); k*u6'IKi.4  
if(header!=null) joDqv,iW8  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &"?99E>  
Utility.log(header+" : "+con.getHeaderField(header)); Dpwqg3,  
else M}j[{wW3  
break; Q_Br{ `c  
} s3T7M:DM4  
} <$@I*xk[  
,N _/J4Us  
wMw}3qX$j  
public void splitterStop() J0 dY%pH#  
{ Vo6+|ztk|  
bStop = true; vsyg u  
} n=PfV3B  
u(fZ^  
jU kxA7 }}  
} 1l/t|M^I  
W mbIz[un  
'=O1n H<  
/* 8{]nS8i  
**FileAccess.java @ze2'56F}  
*//文件访问(定位,写) Q lA?dXQ  
package NetFox; 5 HsF#  
import java.io.*; J>k 6`gw  
aNs8T`  
mo3A*|U  
public class FileAccessI implements Serializable{ ,  O/IY  
: 5['V#(o  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u;]xAr1  
RandomAccessFile oSavedFile; `a:3S@n(}  
long nPos; k$ T  
;X a N  
AAs&P+;  
public FileAccessI() throws IOException qo$ls\[X  
{ yoJ.[M4q  
this("",0); `|Hk+V  
} '!ks $}$`h  
0 )cSm"s  
g1?9ge 1  
public FileAccessI(String sName,long nPos) throws IOException SB08-G2  
{ o<iU;15  
oSavedFile = new RandomAccessFile(sName,"rw"); 1<fW .Q)  
this.nPos = nPos; *sZH3:  
oSavedFile.seek(nPos); 6-uLK'E  
} -%]1q#C>@  
K,JK9)T  
\EU^`o+  
public synchronized int write(byte[] b,int nStart,int nLen) \@yJbhk  
{ {;E6jw@  
int n = -1; A^p{Cq@E  
try{ 9gdK&/ulR  
oSavedFile.write(b,nStart,nLen); (X Oz0.W  
n = nLen; UlXxG|  
} >d=pl}-kOQ  
catch(IOException e) _9t1 aP5  
{ XXhN; -p  
e.printStackTrace (); n-xdyJD  
} _'ebXrbZB  
AD^I1 ]2f  
yNEU/>]>2  
return n; ~,oz hj0f/  
} Rzh.zvxTp  
kxd*B P  
\v6lcAL-  
} Z\Ur F0  
 T&MhSJf#  
HzKY2F(,  
/* @&E IH,c  
**SiteInfoBean.java ,Pcg+^A  
*/ [FrLxU  
package NetFox; czU"  
V2`Ud[  
uDXV@;6<  
public class SiteInfoBean { Z]R#F0"U  
}% q-9  
enZZ+|h  
private String sSiteURL; //Site's URL cV0CI&  
private String sFilePath; //Saved File's Path ,c  ^nW  
private String sFileName; //Saved File's Name "OK[uug  
private int nSplitter; //Count of Splited Downloading File ypG*41  
1AN$s  
ppNMXbXR  
public SiteInfoBean() NN=^4Xpc:  
{//nSplitter的缺省值为5 z'$1$~I  
//default value of nSplitter is 5 qbeUc5`1  
this("","","",5); p%&$%yz$  
} aA52Li  
D>7J[ Yxg-  
J{prI;]K  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (YYg-@IO  
{ GVJ||0D  
sSiteURL= sURL; ;Su-Y!&%  
sFilePath = sPath; W[*xr{0V  
sFileName = sName; H\a"=&M  
this.nSplitter = nSpiltter; [2Zy~`*y{  
0QW=2rs  
wiZ  
} S} OO)  
dd<l;4(  
z)U7  
public String getSSiteURL() Dqii60  
{ |u^S}"@3sU  
return sSiteURL; 5|*`} ;/y  
} N'9T*&o+  
z8awND  
<\<o#Vq  
public void setSSiteURL(String value) C$PS@4'U  
{ 'UWkJ2:!  
sSiteURL = value; {9}CU~R  
} '!`\!=j-`  
(^y"'B  
OVDuF&0  
public String getSFilePath() oV0 45G  
{ &=jPt%7#M  
return sFilePath; 6Q [  
} >FwK_Zd'  
|r Aot2  
Sk>=C0f:  
public void setSFilePath(String value) !pw )sO~  
{ Vi-Ph;6[  
sFilePath = value; f+uyO7  
} +"<+JRI(M5  
 *0^~@U  
F[Mwd &P@  
public String getSFileName() fxPg"R!1i  
{ gAdqZJR%]  
return sFileName; f%@~|:G:  
} =dDPQZEin  
`sT;\  
,P`NtTN-  
public void setSFileName(String value) /CNsGx%%  
{ ?@$xLUHR4  
sFileName = value; .cQO?UKK  
} Wy7w zt  
G/Sp/I<d  
n]' r3  
public int getNSplitter()  XyE$0i~t  
{ ^ZQMRNP{r  
return nSplitter; *}lLV.+A  
} [QgP6f]=  
} #H,oy;Dz  
G]f|?  
public void setNSplitter(int nCount) 8CZfz!2  
{ O;<wD h)Yt  
nSplitter = nCount; M['O`^  
} 77O$^fG2  
} [m0X kvd  
3< ?+Yhq  
>bf.T7wy  
/* mW%8`$rVEO  
**Utility.java F6[F~^9D  
*/ uW!XzX['  
package NetFox; zFExYYd   
HbA/~7  
FefroaJ:u  
public class Utility { n>q!m@ }<  
A|r3c?q  
]<\YEz&A  
public Utility() Tt)z[^)%  
{ 0<\|D^m=&h  
R#4l"  
1$vGQ  
} OA3J(4!"W  
;F"!$Z/  
//线程睡眠 MIIl+   
public static void sleep(int nSecond) y ;[~(Yg[  
{ js81@WX!c  
try{ H u;"TG  
Thread.sleep(nSecond); G9Uc }z  
} Z\CvaX  
catch(Exception e) BeVDTk :  
{ <C'_:&M  
e.printStackTrace (); /"gRyv  
}  80@\e  
} Bgm8IK)6  
a(A~S u97  
//日志 /\/^= j  
public static void log(String sMsg) O0qG 6a  
{ [G|.  
System.err.println(sMsg); ``WTg4C(Y  
} '2r  
<x^$Fu  
Z?'CS|u d  
public static void log(int sMsg) sq_>^z3T  
{ c]|vg=W  
System.err.println(sMsg); n;Oe-+oSC  
} 5Z!$?J4Rl  
} nd8<*ru$  
)_jboaNzwI  
_:m70%i  
/* FQ<x(&/NF  
**TestMethod.java _R ii19k  
*/ k-|g  
package NetFox; OOSf<I*>  
7y|U!r"Y  
D j9aTO  
public class TestMethod { 7@;*e=v  
3k)xzv%r`  
=IMmtOvJ  
public TestMethod() _h-agn4[i  
{ ///xx/weblogic60b2_win.exe 3<r7"/5  
try{ ,IPt4EH$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;\0|1Eem`  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vTK%8qoZ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); k2D*`\ D  
fileFetch.start(); tw$EwNI[  
} J=3{<Xl  
catch(Exception e){e.printStackTrace ();} 4P3RRS  
Pw<?Dw]m  
~DK.Y   
} x *I'Ar  
0(y*EJA$  
U7x  
public static void main(String[] args) V|'@D#\  
{ "mJo<i}  
new TestMethod(); \|Af26  
} .z,-ThTH@\  
} ElW\;C:K*  
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