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http断点续传简单实现(java)

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/* <2R xyoDL6  
**SiteFileFetch.java U HUO9h  
*/ ;V3d"@R,  
package NetFox; -qRO}EF  
import java.io.*; ;:pd/\<  
import java.net.*; ;={Z Bx  
WWYG>C[  
BXo9s~5Q  
public class SiteFileFetch extends Thread { q9"~sCH  
;^:$O6J7T~  
hk1jxnQ h  
SiteInfoBean siteInfoBean = null; //文件信息Bean Mt`XHXTp  
long[] nStartPos; //开始位置 VR0#"  
long[] nEndPos; //结束位置 quw:4W>  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ]6{\`a  
long nFileLength; //文件长度 E.~~.2   
boolean bFirst = true; //是否第一次取文件 V/7?]?!xu  
boolean bStop = false; //停止标志 prg8Iq'w  
File tmpFile; //文件下载的临时信息 A)q,VSR8  
DataOutputStream output; //输出到文件的输出流 4lfJc9J  
"t" &6\  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) >zAI#N4  
public SiteFileFetch(SiteInfoBean bean) throws IOException k|T0Bly3P  
{ QabYkL5@  
siteInfoBean = bean; abM4G  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); XD\Z$\UJE  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); CDM==Xa*  
if(tmpFile.exists ()) \M`fkR,,'  
{ 4\yKd8I  
bFirst = false; 1)m&6:!b  
read_nPos(); 7oI^shk  
} OT5'cl  
else f*SAbDE  
{  g8_IZ(%:  
nStartPos = new long[bean.getNSplitter()]; &vp0zYd+v  
nEndPos = new long[bean.getNSplitter()]; .U !;fJ9  
} >h m<$3  
wc'K=;c  
m=< ;)  
XL7jUi_4:L  
} n`hes_{,g  
@*c ) s_  
L"6@3  
public void run() kY6))9 O  
{ QP e}rQnm  
//获得文件长度 \;A\ vQ[  
//分割文件 5&r2a}K  
//实例FileSplitterFetch J ;wA  
//启动FileSplitterFetch线程 N]sX r  
//等待子线程返回 Ma3Hn  
try{ XJ;JDch  
if(bFirst)  VSkx;P  
{ +<ey Iw  
nFileLength = getFileSize(); cNG6 A4  
if(nFileLength == -1) X7]vXo*  
{ <!vAqqljt  
System.err.println("File Length is not known!"); 4&/-xg87(  
} t%AW0#TZ  
else if(nFileLength == -2) *7I=vro  
{ Ucnit^,  
System.err.println("File is not access!"); !Jj=H()}  
} YtrMJ"  
else z {J1pH_X  
{ a;Y9wn  
for(int i=0;i<nStartPos.length;i++) (Rk g  
{ LHWh-h(s  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); A4?_ 0:<  
} &~Q ?k  
for(int i=0;i<nEndPos.length-1;i++) >:`Y]6z  
{ Q=9S?p M  
nEndPos = nStartPos[i+1]; UmU=3et<Wj  
} y*6r&989  
nEndPos[nEndPos.length-1] = nFileLength; :LFw J  
} yXw xq(32  
} BI=Ie?  
mlgdwM  
\?fl%r2  
//启动子线程 m-a _<xo  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?^&!/,  
for(int i=0;i<nStartPos.length;i++) ;r[=q u\  
{ xTM&SVNbL_  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B%9[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :OBggb#?!  
nStartPos,nEndPos,i); $hO8 S=  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xZmKKKd0*  
fileSplitterFetch.start(); /BVNJNhz  
} [:!#F7O-  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bd"7F{H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FO}4~_W{  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zq]V6.]J  
nEndPos = " + nFileLength); b\?#O}  
// fileSplitterFetch[nPos.length-1].start(); 3<msiC P  
N[ArwV2O  
v.v3HB8p  
//等待子线程结束 7w{`f)~  
//int count = 0; wy_TFV  
//是否结束while循环 U'.>wjO  
boolean breakWhile = false; M)EUR0>8  
9&'Mb[C`"  
J\   
while(!bStop) Ye!=  
{ YKl!M/  
write_nPos(); ,^o^@SI)   
Utility.sleep(500); mXF pGo5 s  
breakWhile = true; ,lA J{5\#  
N &p=4  
Ze Shn  
for(int i=0;i<nStartPos.length;i++) foE2rV/Y  
{ :yk Z7X&  
if(!fileSplitterFetch.bDownOver) i`8!Vm  
{ kZGhE2np  
breakWhile = false; /IV:JVT  
break; Q:VD 2<2  
} ,bmTB ZV  
} a$t [}D2  
if(breakWhile) nhXa&Nro  
break; rmQGzQnun  
4b3p,$BWS  
<k^9l6@  
//count++; WM=kr$/3  
//if(count>4) x'JfRz  
// siteStop(); -07(#>  
} fBd +gT\S  
TJsT .DWW~  
9f,HjRP  
System.err.println("文件下载结束!"); <)n   
} Z@C D1+G  
catch(Exception e){e.printStackTrace ();} /'VCJjzZ  
} ocgbBE  
~T4 =Id  
]P<&CEk  
//获得文件长度 /e{Oqhf[n  
public long getFileSize() ( v ~/glf  
{ 4N` MY8',  
int nFileLength = -1; #2HygS  
try{ tg8VFH2q.z  
URL url = new URL(siteInfoBean.getSSiteURL()); 1NOz $fW  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'OX6e Y5  
httpConnection.setRequestProperty("User-Agent","NetFox"); S-f3rL[?  
2,QkktJLo  
H V   
int responseCode=httpConnection.getResponseCode(); Y @.JW  
if(responseCode>=400) i,yK&*>JJ  
{ $V~%$  
processErrorCode(responseCode); Fx3VQ'%J  
return -2; //-2 represent access is error s9[v_(W  
} At bqj?  
dqKTF_+VhA  
+Qc^A  
String sHeader; p Y>yJ)  
3?5 ~KxOE(  
(J^ Tss  
for(int i=1;;i++) o!\O)  
{ A<.Q&4jb  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #sqDZ]\B  
//Utility.log(in.readLine()); M;43F*   
sHeader=httpConnection.getHeaderFieldKey(i); 9I.v?Tap  
if(sHeader!=null) ^~`8 - TE  
{ P^h2w%6'  
if(sHeader.equals("Content-Length")) Y6D =tb  
{ ryn)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [Z5x_.k"I  
break; ZA9']u%EJ  
} W>DpDrO4ml  
} giu~"#0/F  
else U.^)|IHW  
break; }lxvXVc{I  
} Gg.w-&  
} v"F0$c  
catch(IOException e){e.printStackTrace ();} l5h9Eq  
catch(Exception e){e.printStackTrace ();} s)M2Z3>+  
R<U?)8g,h~  
2bxT%xH:g  
Utility.log(nFileLength); xwRnrWd^6  
M"9 zK[cz  
G8;S`-D1a,  
return nFileLength; rf`Br\g8  
} nL:vRJr-$  
4 ^+hw;  
ASYUKh,h  
//保存下载信息(文件指针位置) PZ ogN  
private void write_nPos() 93!a  
{ X  ]a>  
try{ .y\HQ^j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Maa.>2v<  
output.writeInt(nStartPos.length); rL,)Tc|"  
for(int i=0;i<nStartPos.length;i++) YwF6/JA0^  
{ =6W:O  
// output.writeLong(nPos); `riv`+J{s  
output.writeLong(fileSplitterFetch.nStartPos); @Op8^8$`  
output.writeLong(fileSplitterFetch.nEndPos); AQiP2`?  
} - 5k4vx N}  
output.close(); OUdeQO?  
} Ch.T} %  
catch(IOException e){e.printStackTrace ();} "=".ne  
catch(Exception e){e.printStackTrace ();} E%;'3Qykva  
} &iGl)dDr  
H]!y |p  
W?l .QQk  
//读取保存的下载信息(文件指针位置) vfbe=)}[  
private void read_nPos() K4F!?#  
{ ~lF lv+,%  
try{ & 9]KkY=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t~a$|( 9  
int nCount = input.readInt(); .y0]( h  
nStartPos = new long[nCount]; %zelpBu+  
nEndPos = new long[nCount]; -E500F*b  
for(int i=0;i<nStartPos.length;i++) ,m"ztu-  
{ I+CQ,Zuf  
nStartPos = input.readLong(); XeB>V.<y  
nEndPos = input.readLong(); A5`7o9  
} <eh(~  
input.close(); EIYM0vls(  
} aEk*-v#{  
catch(IOException e){e.printStackTrace ();} 7 IHD?pnZ  
catch(Exception e){e.printStackTrace ();} NSgHO`gU8  
} QhG-1P3#  
>=`c [=:Z_  
rgYuF,BT.  
private void processErrorCode(int nErrorCode) $HXB !$d  
{ 28)TXRr-  
System.err.println("Error Code : " + nErrorCode); b "Mq7&cf  
} #VOjnc/rW  
*M|\B|A.  
z8j(SI;3  
//停止文件下载 &53#`WgJ  
public void siteStop() <{U{pCT%  
{ Fm;)7.% >  
bStop = true; 9V],X=y~  
for(int i=0;i<nStartPos.length;i++) J@GfO\ o  
fileSplitterFetch.splitterStop(); YT5>pM-%  
BH-[q9pf  
0o<q Eo^  
} YMi(Cyja&  
} }]~}DHYr  
//负责部分文件的抓取 ) *A,L%  
**FileSplitterFetch.java '<0q"juXE  
*/  q%k+x)  
package NetFox; TN %"RL  
bSr 'ji  
r9M={jC  
import java.io.*; Z M+Hb_6f  
import java.net.*; {a3kn\6H0  
ZmULy;{<)  
`Q&] dE=  
public class FileSplitterFetch extends Thread { UC1!J =f  
+r0eTP=zf  
VRX" @uCD  
String sURL; //File URL bS<@Rd{g  
long nStartPos; //File Snippet Start Position Jrk^J6aa  
long nEndPos; //File Snippet End Position qp W#!Vbx  
int nThreadID; //Thread's ID 2Z O'X9  
boolean bDownOver = false; //Downing is over [)3 U])w/  
boolean bStop = false; //Stop identical B (1,Rq[  
FileAccessI fileAccessI = null; //File Access interface _onp%*  
p0rwiBC=q  
eCp|QSXE  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >$mSF Jz5S  
{ ^)q2\ YE;  
this.sURL = sURL; (J*w./  
this.nStartPos = nStart; UPKi/)C;  
this.nEndPos = nEnd; 7rSUSra  
nThreadID = id; (oXN>^-D  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lk +K+Ra/  
} DVhTb  
;1.>"zX(  
mbBRuPEa=u  
public void run() R1.sq(z`  
{ Uxemlp%%*  
while(nStartPos < nEndPos && !bStop) 5b#6 Y  
{ qP"JNswI_  
X[Ek'=}  
=4e=wAO(i  
try{ -L9R&r#_e  
URL url = new URL(sURL); 8'lhp2#h  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <KwK tgzs  
httpConnection.setRequestProperty("User-Agent","NetFox"); Uk:.2%S2  
String sProperty = "bytes="+nStartPos+"-"; cU*lB!  
httpConnection.setRequestProperty("RANGE",sProperty); z`/.v&<>V  
Utility.log(sProperty); #Q3PzDfj  
RW 7oL:$dt  
%?f:"  
InputStream input = httpConnection.getInputStream(); $a^isd4  
//logResponseHead(httpConnection); qd+[ShrhqZ  
,Us2UEWNv  
>J}n@MZ  
byte[] b = new byte[1024]; -(w~LT$ "  
int nRead; zw: C*sY  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z"K( bw6  
{ b%;59^4AjD  
nStartPos += fileAccessI.write(b,0,nRead); JYd7@Msfc  
//if(nThreadID == 1) }[z<iij4  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v1r_Z($  
} )_v\{N  
s$Zq/l$1x  
*e<Eu>fW#&  
Utility.log("Thread " + nThreadID + " is over!"); fcICFReyV  
bDownOver = true; 5$oewjLO  
//nPos = fileAccessI.write (b,0,nRead); ^MT9n  
} ChTXvkdH  
catch(Exception e){e.printStackTrace ();} ,iVPcza  
} ]&:b<]K3  
} kV ,G,wo  
h1XMx'}B  
A*;?U2  
//打印回应的头信息 C,r`I/;  
public void logResponseHead(HttpURLConnection con) 8*yo7q&  
{ NGD*ce"w  
for(int i=1;;i++) Q0cY/'>4  
{ x48'1&m  
String header=con.getHeaderFieldKey(i); 7B(bH8  
if(header!=null) `4%;qLxngP  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `\jTpDV_W  
Utility.log(header+" : "+con.getHeaderField(header)); h.V]fS  
else YN@6}B#1  
break; NLQE"\#a  
} %)axGbZG;  
} OB6J.dF[%  
G*\abL  
\C K(;J  
public void splitterStop() JA)o@[l F  
{ "#twY|wW  
bStop = true; Cqgk  
} %f(S'<DhC  
JzMZB"Z?  
5r4gmy>  
} l RDxIuTK  
YZGS-+  
w(/DTQc~d  
/* -@2'I++"@  
**FileAccess.java fpvvV(  
*//文件访问(定位,写) &xiOTkqB  
package NetFox; ;cI#S%uvpn  
import java.io.*; :p<kQ4   
BR36}iS;V  
'Y!pY]Z  
public class FileAccessI implements Serializable{ A XBkJ'jd  
hOPe^e"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l(%k6  
RandomAccessFile oSavedFile; > BNw  
long nPos; b]*X<,p  
hr$Sa  
?j/kOD0  
public FileAccessI() throws IOException _BV`,`8}  
{ QqtC`H\  
this("",0); Hz?!BV0  
} > z=Ou<,  
Zx+cvQ  
rH_Jh}Y  
public FileAccessI(String sName,long nPos) throws IOException f.oP   
{  {l2N&  
oSavedFile = new RandomAccessFile(sName,"rw"); f=ac I|w  
this.nPos = nPos; TMJ9~"IO  
oSavedFile.seek(nPos); )N(9pnyZH  
} LJGJ|P  
pI7Ssvi^  
X9fNGM1  
public synchronized int write(byte[] b,int nStart,int nLen) ,+tPRkwA^  
{ 3J%V%}mD  
int n = -1; u#`+[AC`  
try{ ljPq2v ]  
oSavedFile.write(b,nStart,nLen); 6&89~W{  
n = nLen; yl-fbYH  
} iJdP>x  
catch(IOException e) H9RGU~q4s[  
{ jfUJ37zNZr  
e.printStackTrace (); 5W+{U8\  
} +UxI{,L  
{A|bBg1!  
=fl%8"%N&  
return n;  SLkuT`*  
} XHsd-  
}^"0T-ua  
1SW4Y  
} naz:A  
^7uX$  
Kax#OYLpg  
/* G0}Dq M Ti  
**SiteInfoBean.java eC~ jgB  
*/ U98_M)-%&  
package NetFox; y%4 Gp  
P5xI  
q IM  
public class SiteInfoBean { v ~"Ef_`  
k6@b|  
J58#$NC `'  
private String sSiteURL; //Site's URL @\)fzubu  
private String sFilePath; //Saved File's Path 9e~WK720=  
private String sFileName; //Saved File's Name Z_FNIM0f  
private int nSplitter; //Count of Splited Downloading File M>T[!*nTj  
rvic%bsk  
/D[dO6.  
public SiteInfoBean() 2F1ZAl  
{//nSplitter的缺省值为5 Y0@yD#,0~  
//default value of nSplitter is 5 QY@u}&m%o  
this("","","",5); '[nmFCG%m*  
} "u;YI=+  
7 _g+^e-"  
0Uw ^FcW  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cZ|lCy^  
{ EKuSnlTXba  
sSiteURL= sURL; R2 lXTW*  
sFilePath = sPath; K\P!a@>1  
sFileName = sName; gg[ 9u-  
this.nSplitter = nSpiltter; :a.0he s  
=_ y\Y@J  
nUc;/  
} ,=|4:F9  
/s|{by`we4  
)11W)G`w  
public String getSSiteURL() QR"bYQ  
{ 6NX3"i0 eT  
return sSiteURL; 0|XKd24BN  
} b`CWp;6Y  
; 0ko@ \Lq  
%/T7Z; d  
public void setSSiteURL(String value) ^s{hs(8%R  
{ :p>hW!~  
sSiteURL = value; Ma6W@S  
} ]p]UTCo!'  
S`iR9{+&  
!>n|c$=;qk  
public String getSFilePath() #Fs|f3-@  
{ & [_ZXVva~  
return sFilePath; P~RhUKfd  
} & Kmy}q  
yNa;\UF  
ff E#^|  
public void setSFilePath(String value) GK?4@<fY  
{ .9h)bf+  
sFilePath = value; *Qkc[XHqy  
} t> . Fl-  
3b!,D  
gnLn7?  
public String getSFileName() >A}0Ho  
{ LA4<#KP  
return sFileName; ;`(R7X *3  
} [2 zt ^  
8IGt4UF&?  
_1|$P|$P.  
public void setSFileName(String value) JA^v  
{ 7I}P*%(f  
sFileName = value; #BY`h~&T  
} #@qN8J}R  
OeElMRU"  
SfB8!V|;  
public int getNSplitter() m"d/b~q  
{ i ]o"_=C  
return nSplitter; W7=V{}b+  
} 2Y OKM #N]  
T_;]fPajjD  
DlTR|(AL  
public void setNSplitter(int nCount) w? LrJ37u  
{ |`O7nOM  
nSplitter = nCount; `rb>K  
} 4(cJ^]wb^  
} Z4hLdHo_  
B4g8 ~f  
s8<gK.atl  
/* 4w$_ ]ke  
**Utility.java (\,BxvhG=  
*/ osH Cg  
package NetFox; 9}P"^N  
^6;V}2>v}  
3l4NC03I&  
public class Utility { Tum_aI  
g|%L"-%gJ  
C#Bz >2;#  
public Utility() |< qs  
{ nJZ6? V  
H(-4:BD?  
UMMB0(0D  
} `bG7"o`  
@ -:]P8  
//线程睡眠 9em*r9-  
public static void sleep(int nSecond) ,EpH4*e  
{ jqnCA<G~B-  
try{ }< 5F  
Thread.sleep(nSecond); {i [y9  
} OB-Q /?0  
catch(Exception e) zsXpA0~3s  
{ ..W-76{  
e.printStackTrace (); s9)8b$t]  
} LM)`CELsYc  
} f{&bOF v  
?GT@puJS-  
//日志 @T-p2#&  
public static void log(String sMsg) `>lzlEhKV  
{ ,0N94pKy  
System.err.println(sMsg); +T{'V^  
} #{J,kcxS  
 $_;e>*+x  
1wj:aD?g  
public static void log(int sMsg) I f-_?wZe  
{ T7*wS#z)h  
System.err.println(sMsg); !#yq@2QX  
} &1|?BZv  
} K>/%X!RW  
\2C`<h$fN  
_D, ;MB&7  
/* D=r))  
**TestMethod.java Iah[j,]r  
*/ tt_o$D~kg  
package NetFox; SA"p\}"  
<|B1wa:|  
Q \hY7Xq'  
public class TestMethod { \nqkA{;B{  
p0:kz l4$  
OO) ~HV4\  
public TestMethod() +IFw_3$  
{ ///xx/weblogic60b2_win.exe /=?x{(B>  
try{ #Pk$L+C  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N)2f7j4C &  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z.PBu|Kx  
SiteFileFetch fileFetch = new SiteFileFetch(bean); *fMpZ+;[m  
fileFetch.start(); AyKMhac  
} NAC_pM&B  
catch(Exception e){e.printStackTrace ();} fwR_OB: $  
7- d.ZG  
wK_]/Q-L  
} Z8O n%Mx{"  
c}Z6V1]QP  
&[Xu!LP  
public static void main(String[] args) fV>CZ^=G  
{ k?B[>aQn.0  
new TestMethod(); )!bUR\  
} |SZo' 6  
} %r\n%$@_  
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