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http断点续传简单实现(java)

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/* &I/qG`W  
**SiteFileFetch.java O,'#C\   
*/ E7`qmn  
package NetFox; 64umul  
import java.io.*; +rc SL8C  
import java.net.*; C6]OAUXy:F  
$gvr -~  
?:uNN  
public class SiteFileFetch extends Thread { VD [pZ2;4  
v+6e;xl8  
 z)w-N  
SiteInfoBean siteInfoBean = null; //文件信息Bean : G=FiC  
long[] nStartPos; //开始位置 y' [LNp V  
long[] nEndPos; //结束位置 cU8xUpq  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 <cj{Qk  
long nFileLength; //文件长度 Ryv_1gR!  
boolean bFirst = true; //是否第一次取文件 0` 5e  
boolean bStop = false; //停止标志 u-:Ic.ZV  
File tmpFile; //文件下载的临时信息 'SV7$,mK@  
DataOutputStream output; //输出到文件的输出流  "r$/  
cP rwW 6  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) t,<UohL|z  
public SiteFileFetch(SiteInfoBean bean) throws IOException >bIF>9T  
{ wxdyF&U n  
siteInfoBean = bean; +~35G:&:  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); jatr/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 5k$vlC#[H  
if(tmpFile.exists ()) WU)Ss`s \  
{ gKi{Y1  
bFirst = false; HID([Wk  
read_nPos(); NBOCt)C;H  
} r4Q|5kT*i  
else zK;XF N#U^  
{ e;(  
nStartPos = new long[bean.getNSplitter()]; VaR/o#  
nEndPos = new long[bean.getNSplitter()]; E!mmLVa9  
} qZ+H5AG2  
!Zjq9{t\"  
GBQn_(b9I  
/tj$luls5  
} z9 ($.  
uM S*(L_  
sn{tra  
public void run() Mu&x_&|  
{ fk{0d  
//获得文件长度 m4m<nnM  
//分割文件 DQ80B)<O  
//实例FileSplitterFetch N+g@8Q2s;5  
//启动FileSplitterFetch线程 goZ V.,w  
//等待子线程返回 H"Dn]$Q\Z  
try{ PJ\0JR7a  
if(bFirst) {_>em*Vb  
{ 5o 0Ch  
nFileLength = getFileSize(); kbI/4IRW  
if(nFileLength == -1) NX,-;v  
{ Vw~\H Gs/~  
System.err.println("File Length is not known!"); @PSLs *  
} w/m:{cHk  
else if(nFileLength == -2) 7wVH8^|  
{ ^4pto$#@O:  
System.err.println("File is not access!"); rx!=q8=0R  
} n7! H:{L  
else [TTSA2  
{ WNy3@+@GZ  
for(int i=0;i<nStartPos.length;i++) 46No%cSiG  
{ |J>WC}g@n  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); s V  }+eU  
} =RKSag&  
for(int i=0;i<nEndPos.length-1;i++) bF-"tm  
{ VaLs`q&3>  
nEndPos = nStartPos[i+1]; E6A /SVp  
} -x*2t;%z{U  
nEndPos[nEndPos.length-1] = nFileLength; B\CN<<N>dD  
} o\=n4;S  
} HdX2YPYn;  
bGmx7qt#  
zm#nV Y`  
//启动子线程  .\:J~(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L%\b'fs  
for(int i=0;i<nStartPos.length;i++) 2A:,;~UH  
{ wCKj7y[  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uGVy6,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Da1aI]{I  
nStartPos,nEndPos,i); I'!/[\_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MaY682}|y  
fileSplitterFetch.start(); v"O5u%P  
} '7 )"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mUP.rb6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `V!>J 1x  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s8mr''  
nEndPos = " + nFileLength); ajH"Jy3A  
// fileSplitterFetch[nPos.length-1].start(); N#z~  
cP>o+-)  
~Y!kB:D5;~  
//等待子线程结束 MuI2?:~:*4  
//int count = 0; .*/Fucr  
//是否结束while循环 E6MA?Ax&=  
boolean breakWhile = false; 5.0e~zlM -  
el PE%'  
S: :>N.y  
while(!bStop) $)Bg JDr  
{ \_BkY%a  
write_nPos(); Ym8}ZW-  
Utility.sleep(500); m`A% p  
breakWhile = true; 5Av=3[kh"%  
:k=mzO<&  
gAbD7SE  
for(int i=0;i<nStartPos.length;i++) A%bCMP  
{ +9A\HQ|22  
if(!fileSplitterFetch.bDownOver) obH; g*  
{ 47>>4_Hz  
breakWhile = false; aaW]J mRb  
break; ~$,qgf  
} 7/Il L  
} 3iNkoBCg  
if(breakWhile) @%ECj)u`O  
break; f'Mop= .  
,_ 2x{0w:>  
K\?]$dK5  
//count++; !36]ud&  
//if(count>4) /Lf6WMit  
// siteStop(); hpbf&S4  
} PAF8W lg  
1Y j~fb(  
gE7L L=x  
System.err.println("文件下载结束!"); "&+3#D >  
} b1?xeG#  
catch(Exception e){e.printStackTrace ();} =d`5f@'rl  
} t*S." q  
/bRg?Q  
Xl-e !  
//获得文件长度 :l\V'=%9'@  
public long getFileSize() :l u5Uu~  
{ *ZCn8m:-+  
int nFileLength = -1; _2ef LjXQ  
try{ $.E6S<(h  
URL url = new URL(siteInfoBean.getSSiteURL()); -G|a*^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P ,mN >  
httpConnection.setRequestProperty("User-Agent","NetFox"); Gu0 ,)jy\  
# TkR  
3R$Z[D-  
int responseCode=httpConnection.getResponseCode(); 'Prxocxq  
if(responseCode>=400) Ri*3ySyb  
{ 2[yBD-":  
processErrorCode(responseCode); N:5[,O<m_  
return -2; //-2 represent access is error |UUdz_i!:  
} r?$ ?;%|C  
w}cY6O,1  
dl]#  
String sHeader; W7No ls{  
ki]ti={12  
k ]a*&me  
for(int i=1;;i++) 9)dfL?x8V{  
{ $% k1fa C  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $4=f+ "z  
//Utility.log(in.readLine()); RVw9Y*]b  
sHeader=httpConnection.getHeaderFieldKey(i); clO,}Ph>  
if(sHeader!=null) uKr1Z2  
{ SI:ifR&T  
if(sHeader.equals("Content-Length")) 2][DZl  
{ 4Ft1@  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  Ukz;0q  
break; V4w=/e _  
} Rd*[%)  
} ~%k?L4%  
else ~p1EF;4#  
break; X@2-*so<  
} k=ytuV\  
} S::=85[>z  
catch(IOException e){e.printStackTrace ();} \E1U@6a  
catch(Exception e){e.printStackTrace ();} 32)tJ|m  
QCOo  
^rNUAj9Z  
Utility.log(nFileLength); +C]&2zc.  
j{++6<tr  
?X$, fQ#F|  
return nFileLength; giY80!GX  
} }ut]\]b  
<U Zd;e@  
7L5P%zLtB  
//保存下载信息(文件指针位置) D=f7NVc>Q  
private void write_nPos() : esg(  
{ z,SYw &S  
try{ Y$>-%KcKeI  
output = new DataOutputStream(new FileOutputStream(tmpFile)); bzpFbfb  
output.writeInt(nStartPos.length); m!n/U-^  
for(int i=0;i<nStartPos.length;i++) 3 fj  
{ p/6zEZ*  
// output.writeLong(nPos); S^I,Iz+`S'  
output.writeLong(fileSplitterFetch.nStartPos); Dr<='Ux[5  
output.writeLong(fileSplitterFetch.nEndPos); k`KGB  
} <!d"E@%v@  
output.close(); DbI!l`Vn4  
} v5}X+'  
catch(IOException e){e.printStackTrace ();} {lG@hN'  
catch(Exception e){e.printStackTrace ();} Rfb?f} j  
} hS [SRa'.  
#Il_J\#  
t0&@h\K  
//读取保存的下载信息(文件指针位置) SuBeNA[&  
private void read_nPos() IXLO>>`  
{ EV M7Q>  
try{ NcS.49  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w42OF7f  
int nCount = input.readInt(); UKd'+R]  
nStartPos = new long[nCount]; 2.uA|~qH  
nEndPos = new long[nCount]; B:TR2G9UT  
for(int i=0;i<nStartPos.length;i++) @LE[ac  
{ f7urJ'!V  
nStartPos = input.readLong(); X?r48l??  
nEndPos = input.readLong(); cV K7  
} 0rSIfYZa  
input.close(); \`.F\ Z  
} E8\XNG)V4  
catch(IOException e){e.printStackTrace ();} -[7O7'  
catch(Exception e){e.printStackTrace ();} #U7_a{cn"M  
} )P&9A)8  
y8Xv~4qQW  
5i6 hp;=  
private void processErrorCode(int nErrorCode) >B -q@D  
{ AIl4]F5I  
System.err.println("Error Code : " + nErrorCode); ~!iQ6N?PY  
} B/f0P(7  
 }alj[)  
<~emx'F|  
//停止文件下载 }3 m0AQ;K  
public void siteStop() FjfN3#qlg  
{ 9W7#u}Z  
bStop = true; j|fd-<ng  
for(int i=0;i<nStartPos.length;i++) le)DgIT>=  
fileSplitterFetch.splitterStop(); 8ip7^  
|f( ~@Q:  
|k 2"_  
} )+y G+  
} 8;P2A\ X  
//负责部分文件的抓取 7v}x?I  
**FileSplitterFetch.java 1MsWnSvzf  
*/ '!h/B;*(  
package NetFox; 4Cb9%Q0  
u^W2UE\  
_,AzJ^  
import java.io.*; E|EgB33S  
import java.net.*;  NW9n  
?9MVM~$  
10[Jl5+t  
public class FileSplitterFetch extends Thread { yq[Cq=rBk  
n| O [a6G  
yqOuX>m1c  
String sURL; //File URL e&q?}Ho  
long nStartPos; //File Snippet Start Position  l]!9$  
long nEndPos; //File Snippet End Position '(+<UpG_Q}  
int nThreadID; //Thread's ID 8y';\(;  
boolean bDownOver = false; //Downing is over v`[Eb27W.  
boolean bStop = false; //Stop identical N^0uit  
FileAccessI fileAccessI = null; //File Access interface i8X`HbmN  
;Q0bT`/X  
=1;=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9W`Frx'h1  
{ NmIHYN3  
this.sURL = sURL; B6P|Z%E;D6  
this.nStartPos = nStart; V}w;Y?] J  
this.nEndPos = nEnd; a T  l c  
nThreadID = id; M[ 5[N{  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ks;% *d  
} `\Ku]6J]5  
.ae O}^  
Px@/Q  
public void run() S&jesG-F  
{ S]3Ev#>  
while(nStartPos < nEndPos && !bStop) R\Z: n*  
{ NF$\^WvYSP  
N[|Nxm0z/C  
X~.f7Ao[  
try{ &xZyM@  
URL url = new URL(sURL); AN:@fZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Pi2|  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;!@EixN-YH  
String sProperty = "bytes="+nStartPos+"-"; =ziwxIo6  
httpConnection.setRequestProperty("RANGE",sProperty); U!w1AY|  
Utility.log(sProperty); nQK|n^AU/  
>k7q g$  
E .6HpIx  
InputStream input = httpConnection.getInputStream(); 4A`NJ  
//logResponseHead(httpConnection); -|yb[~3  
AF,BwLN  
HG >j5  
byte[] b = new byte[1024]; wmr-}Y!9u%  
int nRead; 4b]a&_-}  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %~ |HFYd  
{ "%2xR[NF  
nStartPos += fileAccessI.write(b,0,nRead); ~vdkFc(8B  
//if(nThreadID == 1) W{cY6@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -_VG;$,jE  
} }f>H\iJe  
+ bhym+  
)wXuwdc[  
Utility.log("Thread " + nThreadID + " is over!"); C R<`ZNuWz  
bDownOver = true; Mq%,lJA\  
//nPos = fileAccessI.write (b,0,nRead); 7YWNd^FI V  
} HHk)ZfWRo  
catch(Exception e){e.printStackTrace ();} Y]aW)u  
} `:{B(+6  
} }*U[>Z-eO  
0Sl]!PZR1  
-5G)?J/*  
//打印回应的头信息 96Wp!]*  
public void logResponseHead(HttpURLConnection con) =;~I_)Pg1  
{ 1{"llD  
for(int i=1;;i++) ?z-}>$I;  
{ ^>4o$}  
String header=con.getHeaderFieldKey(i); OvL\u{(<F  
if(header!=null) %rKK[  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o@>? *=  
Utility.log(header+" : "+con.getHeaderField(header)); ER&UBUu"  
else t6N*6ld2b  
break; q!'rz  
} Z@D*1\TG=  
} X+8B!F  
|tMn={  
/x@RNdKv  
public void splitterStop() c2SC|s]  
{ P3tx|:gV  
bStop = true; G1T^a>tj4  
} Q'apG)0I  
8 }'|]JK  
Nf,Z;5e  
} VU|dV\>  
jLg@FDb~  
-#`c5y}P  
/* "7%:sty  
**FileAccess.java omZO+=8Q  
*//文件访问(定位,写) -PB[-CX  
package NetFox; [^H"FA[  
import java.io.*; w&&2H8  
'$|UwT`s  
#>;FUZuJr  
public class FileAccessI implements Serializable{ ]J1S#Q5'  
ig"uXs  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d=.2@Ry  
RandomAccessFile oSavedFile; 3Q}$fQ&S  
long nPos; !,$i6gm  
^u)z{.z'H/  
qf'm=efRyu  
public FileAccessI() throws IOException uw\1b.r'B  
{ #PLEPB  
this("",0); Sywu=b  
} 6x{<e4<n  
Tz&Y]#h_  
I lR\  #  
public FileAccessI(String sName,long nPos) throws IOException ?gGt2O1J  
{ yQS+P8x&|]  
oSavedFile = new RandomAccessFile(sName,"rw"); <M?:  
this.nPos = nPos; |Q~cX!;  
oSavedFile.seek(nPos); 6bc3 37b  
} ^:, l\Y  
RH0>ZZR  
c2l_$p  
public synchronized int write(byte[] b,int nStart,int nLen) i y YJR  
{ mbl]>JsQD  
int n = -1; ,n,RFa  
try{ jP vDFT^d/  
oSavedFile.write(b,nStart,nLen); ]6Ug>>x5  
n = nLen; \b8sG"G  
} C=Fzu&N}  
catch(IOException e) FaTa(3$%  
{ ~Z/ ^c,[:  
e.printStackTrace (); aAvsb$  
} ,"-Rf<q/  
S&nxok`e^  
"tit\a6\(  
return n; f}c\_}(  
} ]-o"}"3Ef  
<<A`aU^fX  
IHfzZHy  
} S&C1TC  
l*b)st_p%  
3q[WHwmm  
/* l7(!`NPbC  
**SiteInfoBean.java gCd`pi 8  
*/ bSwWszd~  
package NetFox; ({0)@+V8  
OIHz I2{  
?{"mP 'dD  
public class SiteInfoBean { Nb2Qp K  
9&%fq)gS  
a\uie$"cr]  
private String sSiteURL; //Site's URL /T^ JS  
private String sFilePath; //Saved File's Path 5M]z5}n/  
private String sFileName; //Saved File's Name ek aFN\  
private int nSplitter; //Count of Splited Downloading File cR-~)UyrO  
Ax3W2s  
)Ag/Qep  
public SiteInfoBean() ( <t_Pru  
{//nSplitter的缺省值为5 9ILIEm:  
//default value of nSplitter is 5 tHD  
this("","","",5); `+lHeLz':  
} 6< J #^ 6  
YO{GU7  
$v.C0 x  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9_ICNG%  
{ M/PFPJ >`  
sSiteURL= sURL; $DFv30 f  
sFilePath = sPath; QlFZO4 P3|  
sFileName = sName; +YOKA*  
this.nSplitter = nSpiltter; wCs3:@UH  
7z6 b@$,  
ub0zJTFJ#  
} k@>\LR/v  
yDb'7(3-  
vqslirC  
public String getSSiteURL() P=L$;xgp  
{ ;cQW sTfT  
return sSiteURL; _,Fny_u=;  
} _fFU#k:MU  
1PaUI#X"2F  
A \rt6/  
public void setSSiteURL(String value) Q0?\]2eet9  
{ gIWrlIV{9  
sSiteURL = value; mAgF73,3  
} L(;WxHL  
 , iNv'  
U;_[b"SW%  
public String getSFilePath() 4Ph0:^i_  
{ vP%tk s+.  
return sFilePath; &MmU  
} Hi! Jj  
LVIAF0kX  
q:>^ "P{  
public void setSFilePath(String value) &ej8mq"\  
{ 3>ex5  
sFilePath = value; Z.L?1V8Q1  
} foF19_2 ,  
>t,M  
%1 KbS [  
public String getSFileName() ?)Nj c&G  
{ uaw~r2  
return sFileName; o!TQk{0  
} dCYCHHHF  
Zt -1h{7  
dBsX*}C  
public void setSFileName(String value) h[KvhbD3   
{ uy_wp^  
sFileName = value; cxeghy:;U  
} RT/o$$  
oq/G`{`\  
%\O#&=$E  
public int getNSplitter() tary6K9K+  
{ 3H\w2V  
return nSplitter; 3FSqd<t;D  
} g3n'aD@'x  
m8Vdb"0  
Y&H}xn  
public void setNSplitter(int nCount) h-a!q7]l  
{ rj ]F87"  
nSplitter = nCount; ))D:8l@  
} .D,p@4  
} gbOpj3  
E "iUq  
(;x3} ]  
/* <>eOC9;VY  
**Utility.java KT|RF  
*/ mpC`Yk  
package NetFox; Ok5<TZ6t4k  
iF5'ygR-Z  
c:S] R"  
public class Utility { W+wA_s2&D  
5V[oE\B  
ulT8lw='  
public Utility() WFR?fDtE  
{ l5%G'1w#,j  
$w)~O<_U  
MfO:m[s  
} 7`vEe 'qz  
O-]mebTvw  
//线程睡眠  %R#L  
public static void sleep(int nSecond) e:E0"<  
{ 'oNO-)p\#!  
try{ DBLk!~IF  
Thread.sleep(nSecond); 8bK|:B#6,  
} _$NIp `d  
catch(Exception e) q>f<u&  
{ C$Lu]pIL*  
e.printStackTrace (); r0t^g9K0  
} (2ur5uk+  
} wHZW `  
@Q&3L~K"  
//日志 I +5)Jau^S  
public static void log(String sMsg) )M=ioE8`h  
{ I&?Qq k  
System.err.println(sMsg); Xdi:1wW@p  
} B!{d-gb  
~ * :F{  
7g=2Z[o  
public static void log(int sMsg) k$ 5 s{q  
{ f:*vr['d  
System.err.println(sMsg); G)#$]diNuX  
} 1"8yLvtn  
} :(dHY  
a8u 9aEB  
J]W5[)L  
/* <9ig?{'  
**TestMethod.java CO-_ea U(  
*/ GWsE;  
package NetFox; rqv))Zo`  
{l_{T4xToB  
NW~z&8L  
public class TestMethod { c,so`I3rI  
u$%t)2+$4  
U<XSj#&8|  
public TestMethod() *vgl*k?)  
{ ///xx/weblogic60b2_win.exe R(.}C)q3  
try{ +[\eFj|=  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,h|qi[7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f~E*Zz`;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vc^HVyAx@n  
fileFetch.start(); _0+0#! J!  
} 6s,uXn  
catch(Exception e){e.printStackTrace ();} ^@P1 JNe  
I8oo~2Q w  
a`Gx=8  
} AV 8n(  
"G >3QL+O|  
>+. ( r]  
public static void main(String[] args) [{4 MR%--  
{ T0)4v-EO  
new TestMethod(); js1!9%BV  
} y"]n:M:(  
} y(R? ,wa=]  
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