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http断点续传简单实现(java)

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/* PoZ$3V$(Lz  
**SiteFileFetch.java uNy-r`vg  
*/ ->qRGUW  
package NetFox; JRBz/ j  
import java.io.*; + _ehzo97  
import java.net.*; T} \>8EEG  
();Z,A  
%o9mG<.T  
public class SiteFileFetch extends Thread { iOm&(2/  
)Fd)YJVR  
ZWGelZP~  
SiteInfoBean siteInfoBean = null; //文件信息Bean yVzV]&k  
long[] nStartPos; //开始位置 eAO@B  
long[] nEndPos; //结束位置 I!F&8B+|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 zk }SEt-  
long nFileLength; //文件长度 8r}tf3xMCM  
boolean bFirst = true; //是否第一次取文件 fBTNI`#  
boolean bStop = false; //停止标志 &7kLSb&|;  
File tmpFile; //文件下载的临时信息 DaH4Br.2  
DataOutputStream output; //输出到文件的输出流 W\Il@Je;  
3q'nO-KJ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) `!N.1RP _  
public SiteFileFetch(SiteInfoBean bean) throws IOException [*K9V/  
{ n{|j#j  
siteInfoBean = bean; D7R;IA-w  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 4Tuh]5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6jMc|he  
if(tmpFile.exists ()) a@|`!<5  
{ \B 8j9  
bFirst = false; Fu?_<G%Ynp  
read_nPos(); 1_&W1o  
} Lniz>gSc  
else CZy!nR!  
{ Oc~<`C~  
nStartPos = new long[bean.getNSplitter()]; Y)8 Py1}  
nEndPos = new long[bean.getNSplitter()]; XR=ebl  
} %N\45nYU:  
!*^+7M  
e}gGl<((g  
O&CY9 2)Lk  
} REc90v2"  
=H-BsX?P  
/5 KY6XxR  
public void run() mr>E'd.'  
{ rf/]VAK  
//获得文件长度 1"A"AMZf  
//分割文件 T*k{^=6"!  
//实例FileSplitterFetch s Wj:m)  
//启动FileSplitterFetch线程 DbI)tDi5D  
//等待子线程返回 "@+Z1k-8U  
try{ {JQV~rfh`  
if(bFirst) m,5m'9 dj  
{ abVEi[nP  
nFileLength = getFileSize(); X.e4pLwGK  
if(nFileLength == -1) uf )!SxT  
{ Ayw {I#"  
System.err.println("File Length is not known!"); +IGSOWL  
} &mJm'Ks  
else if(nFileLength == -2) ;[C_ho  
{ yqb$,$  
System.err.println("File is not access!"); c ]ll89`||  
} gW G>}M@  
else \= 6dF,V  
{ oj6=.   
for(int i=0;i<nStartPos.length;i++) )CH\]>-FO  
{ 7CU<R9Kl  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6C_H0a/h&  
} d^Cv9%X  
for(int i=0;i<nEndPos.length-1;i++) &x.5TDB>%  
{ o -x=/b  
nEndPos = nStartPos[i+1]; ^6UE/4x!y  
} pmUC4=&e  
nEndPos[nEndPos.length-1] = nFileLength; &)Vuh=  
} T~lHm  
} _y[B/C,q  
#cl|5jm+m#  
V#&S&dn  
//启动子线程 Y,KSr|vG  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ){J,Z*&  
for(int i=0;i<nStartPos.length;i++) uq!d8{IMu  
{ Re;[S[D7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (^|vN ;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I~M@v59C  
nStartPos,nEndPos,i); Wh?3vZ^  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T ^`R  
fileSplitterFetch.start(); *kGk.a=  
} @vi;P ^1!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F^DDN7AKH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k+u L^teyS  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XJ1<!tl  
nEndPos = " + nFileLength); Vg`32nRN  
// fileSplitterFetch[nPos.length-1].start(); yD^Q&1  
c_6~zb?k+m  
QlnI&o  
//等待子线程结束 $=!_ !tr  
//int count = 0; OLJ|gunA#  
//是否结束while循环 !y;xt?  
boolean breakWhile = false; vcp[$-$QGJ  
KFHcHz  
l !R >I7  
while(!bStop) KupQtT<  
{ {@67'jL  
write_nPos(); PAjH*5I A  
Utility.sleep(500); =.q8*7UY  
breakWhile = true; Hc-68]T  
3AC/;WB9  
uWrvkLGN  
for(int i=0;i<nStartPos.length;i++) g/z7_Aq/  
{ C1(0jUz  
if(!fileSplitterFetch.bDownOver) ^' b[#DG>F  
{ V%w]HIhq  
breakWhile = false; $@ZrGT  
break; 3B ;aoejHm  
} '_M"yg6d  
} :&=`xAX-  
if(breakWhile) VL@eR9}9K  
break; $s9YU"  
"xMnD(p  
[G}l;  
//count++; k%sh ;1.  
//if(count>4) uRRp8hht  
// siteStop(); #7,;/rtO7  
} 8CGjI?j  
F@@6D0\X?  
@O&;%IZMY  
System.err.println("文件下载结束!"); 2u^/yl  
} ;fKFmY41  
catch(Exception e){e.printStackTrace ();} /: }"Zb  
} ~`CWpc:  
wb (quu  
k9o LJ<.k  
//获得文件长度 e_t""h4D  
public long getFileSize() <.c#l':  
{ 8s<t* pI2  
int nFileLength = -1; QR{pph*zn-  
try{ `Ct fe8  
URL url = new URL(siteInfoBean.getSSiteURL()); ood,k{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2mPU /  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^yVKW5x  
+FlO_=Bu  
-@G,Ry-\t  
int responseCode=httpConnection.getResponseCode(); S5xum_Dq  
if(responseCode>=400) !:<n]-U  
{ P4dhP-t  
processErrorCode(responseCode); ]^DNzqu=@h  
return -2; //-2 represent access is error ~&T%u.u 7  
} lX|d:HFtP  
>_LZD4v! <  
Z'4oE )  
String sHeader; iz\GahK  
}*M>gvPo  
Yuqt=\? #  
for(int i=1;;i++) 4^AdSuV  
{ Qj',&b  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .l ufE  
//Utility.log(in.readLine()); e"ur+7  
sHeader=httpConnection.getHeaderFieldKey(i); 5"I8ric  
if(sHeader!=null) /.%AE|0+X  
{ tU >?j1  
if(sHeader.equals("Content-Length")) H.]rH,8  
{ 4ai|*8.  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ! p|d[  
break; md`"zV  
} `_5{: 9N$  
} gOKF%Ej31T  
else #u<n .  
break; 5Uha,Q9SA  
} Jde@T h  
} K&>+<bJ_  
catch(IOException e){e.printStackTrace ();} a+ lGN  
catch(Exception e){e.printStackTrace ();} _h8|shyP  
%cFqD &6  
O7D61~G]  
Utility.log(nFileLength); ;dE'# Kb  
gj-MkeI)  
Dt\rMSjZ9  
return nFileLength; "YePd * W  
} ^OnZ9?C{R  
&3%V%_  
MY" 8!  
//保存下载信息(文件指针位置) eg Zb)pP  
private void write_nPos() 4vbtB2  
{ LP- _i}Kq  
try{ /D&7 \3}  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 68-2EWq  
output.writeInt(nStartPos.length); l#k&&rI5x.  
for(int i=0;i<nStartPos.length;i++) 'n4$dv% q  
{ X4Y!Z/b  
// output.writeLong(nPos); T?V!%AqY:  
output.writeLong(fileSplitterFetch.nStartPos); t }q \.  
output.writeLong(fileSplitterFetch.nEndPos); AI\|8[kf0  
} s2ixiv=  
output.close(); c&a.<e3mL  
} TIre,s)_  
catch(IOException e){e.printStackTrace ();} 2u?k;"]V  
catch(Exception e){e.printStackTrace ();} f15f)P  
} |w w@V<'/#  
1a>TJdoa  
(,!G$~Sy  
//读取保存的下载信息(文件指针位置) vv5 uU8  
private void read_nPos() OX[pK_:`l  
{ $~FnBD%|{  
try{ }hyl)?*~  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pGdo:L?  
int nCount = input.readInt(); vo JmNH  
nStartPos = new long[nCount]; mx;1'!'fr  
nEndPos = new long[nCount]; 7\nR'MOZ  
for(int i=0;i<nStartPos.length;i++) Tq*K =^  
{ t2 0Es  
nStartPos = input.readLong(); $K}Y  
nEndPos = input.readLong(); -N~eb^3[c  
} S<bsrS*$  
input.close(); ;j^C35  
} vm Y*K  
catch(IOException e){e.printStackTrace ();} 1NQstmd{  
catch(Exception e){e.printStackTrace ();} bfl%yGkd/|  
} Hm*?<o9mxC  
"D1u2>(  
i]M:ntB"  
private void processErrorCode(int nErrorCode) 0;  BX  
{ X[r\ Qa  
System.err.println("Error Code : " + nErrorCode); .T|1l$Jn  
} i_M0P12  
!H/5Ud9  
bIP%xl Vp  
//停止文件下载 1'Y7h;\~\  
public void siteStop() mO(A'p "b  
{ &h_do8R  
bStop = true; eUeOyC  
for(int i=0;i<nStartPos.length;i++) N^;rLrm*  
fileSplitterFetch.splitterStop(); C6ry]R@  
(f `zd.  
aq-R#q  
} ,3~[cE<4  
} .qGfLvx%  
//负责部分文件的抓取 gOL-b9W  
**FileSplitterFetch.java Lx#CFrLQ*  
*/ .R5(k'g?  
package NetFox; 6h%_\I.Z[[  
/_.1f|{B  
Bq4^nDK  
import java.io.*; ,ctm;T1H+  
import java.net.*; {RPZq2Tpc  
!aQQq[  
X8Y)5,`s  
public class FileSplitterFetch extends Thread { ZtPnHs.x  
uk=f /nT  
Zm+QhnY|  
String sURL; //File URL iz @LS  
long nStartPos; //File Snippet Start Position 4<(U/58a*  
long nEndPos; //File Snippet End Position `_Fxb@"R  
int nThreadID; //Thread's ID Hu-Y[~9^L:  
boolean bDownOver = false; //Downing is over DL]\dD   
boolean bStop = false; //Stop identical 3L1MMUACL  
FileAccessI fileAccessI = null; //File Access interface ~H1 ZQ[  
MR`lF-|a|  
5%1a!M M M  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6<qVeO&uZ  
{ 9XEP:}5,  
this.sURL = sURL; Oi-= Fp  
this.nStartPos = nStart;  A4  
this.nEndPos = nEnd; cypb 6Q_  
nThreadID = id; S2,tv  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -gK*&n~  
} vn5O8sD  
}$E341@  
_KZ&/  
public void run() ;VW->i a6  
{  ; V)jC  
while(nStartPos < nEndPos && !bStop) &&$,BFY4  
{ TcKt   
Pg\!\5  
 'VzYf^  
try{ {#C)S&o)6  
URL url = new URL(sURL); (YC{BM}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0LD$"0v/C3  
httpConnection.setRequestProperty("User-Agent","NetFox"); L=#nnj-  
String sProperty = "bytes="+nStartPos+"-"; Uuq*;L  
httpConnection.setRequestProperty("RANGE",sProperty); On*pI37(\  
Utility.log(sProperty); kX)QHNzP  
Um2RLM%  
_6!@>`u~  
InputStream input = httpConnection.getInputStream(); v-ZTl4j$  
//logResponseHead(httpConnection); -J' 0qN!  
Zc|V7 +Yx  
odsLFU(  
byte[] b = new byte[1024]; ,6AnuA  
int nRead; U *K6FWqiB  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VAnP3:  
{ > Sc/E}3  
nStartPos += fileAccessI.write(b,0,nRead); "%E<%g  
//if(nThreadID == 1) KbTd`AIL  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s9aa _Th  
} u/ZV35z  
M,we9];N  
Q@0Zh, l  
Utility.log("Thread " + nThreadID + " is over!"); -Wm'@4bH  
bDownOver = true; lv!8)GX|  
//nPos = fileAccessI.write (b,0,nRead); 3)0z(30  
} gUWW}*\ U  
catch(Exception e){e.printStackTrace ();} E - +t[W  
} T:=ST3#m  
} =;A >1g$  
G5,g$yNs  
?ytY8`PC  
//打印回应的头信息 a>8&B  
public void logResponseHead(HttpURLConnection con) 6QM$aLLP?  
{ dng^#|X)?  
for(int i=1;;i++) R>T9 H0  
{ CAa&,ZR  
String header=con.getHeaderFieldKey(i); PP&9ORG  
if(header!=null) f~t5[D(\Q,  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); me  ,lE-  
Utility.log(header+" : "+con.getHeaderField(header)); KEfwsNSc%  
else p G(Fw>  
break; OuMj%I  
} dC(5I{I|  
} =)YDjd_=z  
FaQz03N\  
V:<Z   
public void splitterStop() >QSlH]M  
{ >1  %|T  
bStop = true; 7xh91EU:4  
} U%r|hn3  
!%Bhg?  
u2 t=*<X  
} RaC8Sq7hW  
*4OB 88$  
8T5W6Zs1  
/* 76(/(v.x  
**FileAccess.java !x[].Urj  
*//文件访问(定位,写) Pe/8=+qO  
package NetFox; 6lob&+  
import java.io.*; ?M B Od9  
AwtiV-w  
)<(3 .M  
public class FileAccessI implements Serializable{ p)Fi{%bc  
J;*2[o.N  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Mb:>  
RandomAccessFile oSavedFile; YkF52_^_  
long nPos; sv)4e)1  
8DkZ @}  
o3cE.YUF  
public FileAccessI() throws IOException PS$g *x  
{ tSVU,m  
this("",0); .2V?G]u  
} ok1-`c P  
e(H{C  
>ud u~  
public FileAccessI(String sName,long nPos) throws IOException 7G=Q9^J.H  
{ ijACfl{!:t  
oSavedFile = new RandomAccessFile(sName,"rw"); +:3s f%0  
this.nPos = nPos; N{#9gr3zi  
oSavedFile.seek(nPos); yA~1$sA1  
} d]vom@iI  
y<kg;-& 8  
s1bb2R  
public synchronized int write(byte[] b,int nStart,int nLen) uaqV)H  
{ i hcSSUm  
int n = -1; nm,(Wdr  
try{ &mkL4 jXG  
oSavedFile.write(b,nStart,nLen); ,wZq ~; 2  
n = nLen; a[jNT$8  
} *nB-] w/  
catch(IOException e) "#P#;]\`  
{ #'4Psz  
e.printStackTrace (); !.{"Ttn;s  
} 7Qd boEa  
_'Rg7zHTp-  
-ND1+`yD  
return n; !@>q^_Gez  
} cq~~a(IS  
2oo\SmO]  
J\hqK*/8  
} Ze?n Q-  
4mvnFY}   
#<d'=R[ AK  
/* \Nj#1G  
**SiteInfoBean.java L),r\#Y(v  
*/ {__NVv  
package NetFox; @$1jp4c   
G^:?)WRG  
afE8Kqa:H  
public class SiteInfoBean { 7LsVlT[  
"dHo6CT,y_  
]F3fO5Z  
private String sSiteURL; //Site's URL %awr3h>$  
private String sFilePath; //Saved File's Path 5[]Yxl  
private String sFileName; //Saved File's Name 5!BW!-q  
private int nSplitter; //Count of Splited Downloading File HV{W7)  
 0:$pJtx"  
O~|Y#T  
public SiteInfoBean() :xk+`` T  
{//nSplitter的缺省值为5 r-No\u_  
//default value of nSplitter is 5 piFZu/~Gq\  
this("","","",5); 8WpZ "  
} @w(X}q1  
Z+_xX  
Y+eDE:4  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |3g'~E?$  
{ %$N,6}n  
sSiteURL= sURL; <Qt9MO`a  
sFilePath = sPath; \46*4?pP  
sFileName = sName; cNMDI  
this.nSplitter = nSpiltter; HMhdK  
:Sn4Pg `Q  
OVGB7CB]S  
} .:O($9^Ho  
:r7!HG _  
!Y 9V1oVf"  
public String getSSiteURL() 7bQST0 ?  
{ Ymf@r?F<  
return sSiteURL; K5F;/ KR"  
} ^ywDa^;-  
uSv]1m_-]  
H.[nr:  
public void setSSiteURL(String value) [x'D+!  
{ _k#GjAPM  
sSiteURL = value; GK [Hs 1/  
} Jv kTfTE7  
#'n.az=1  
M\RHFTB<C  
public String getSFilePath() hFnUw2 6P  
{ )Myx(w"S  
return sFilePath; yd[4l%G(zS  
} |uI~}pSG  
@}pcj2K#  
_na/&J 6  
public void setSFilePath(String value) |l@z7R+4*  
{ WM7LCP  
sFilePath = value; *JAC+<~d  
} GI>(S  
[=cYsW%WG  
g_rk_4]  
public String getSFileName() u> =\.d <  
{ @>&b&uj7T  
return sFileName; +U4';[LG1C  
} E{}J-_oS45  
d[Zx [=h  
!?lvmq  
public void setSFileName(String value) c}s#!|E0v  
{ Wiw~oXo  
sFileName = value; BAi`{?z$<  
} S(/ ^_Y  
'}:(y$9.`  
a^_W}gzzd  
public int getNSplitter() >v f-,B  
{ (EjlnG}5l  
return nSplitter;  FjMKb  
} ^XG$?2<U  
9_8\xLk  
) I(9qt>Y  
public void setNSplitter(int nCount) gyegdky3  
{ }R%*J  
nSplitter = nCount; nM *}VI  
} 'Ydr_Ses  
} #m;o)KkH$r  
+3sbpl2}  
7]ySj<1  
/* N1$PW~)Y  
**Utility.java `jyyRwSoe  
*/  P1)87P  
package NetFox; O*Y?: t  
].2t7{64  
:4\%a4{Ie  
public class Utility { k7j[tB#  
CD5% iFy  
My Ky*wD  
public Utility() 6uKP BL@,  
{ ; 6PRi/@  
BoOuN94  
u~>G8y)k9O  
} gXU(0(Gq  
|Y?<58[!)  
//线程睡眠 q8n@fi6  
public static void sleep(int nSecond) y#8 W1%{x  
{ i`W~-J  
try{ U| ?68B3  
Thread.sleep(nSecond); mU"Am0Bdjq  
} Y[_|sIy*  
catch(Exception e) 'X6Z:dZY  
{ _1mpsY<k  
e.printStackTrace (); X|G[Ma?   
} 2-jXj9kp`  
} f~/hsp~Hp  
7WY~v2SDF  
//日志 1Kr$JIcd  
public static void log(String sMsg) z30 mk  
{ D u T6Od/f  
System.err.println(sMsg); sv!v`zh  
} ?k($Tc&Q  
=F}qT|K  
o!U(=:*b  
public static void log(int sMsg) UFu0{rY_  
{ r=SC bv  
System.err.println(sMsg); q2'}S A/  
} !^s -~`'\~  
} N%ccy?B  
d R=0K  
U@CAQ?  
/* ob'" ^LO\  
**TestMethod.java #XB3Wden2  
*/ TU58  
package NetFox; gK@`0/k{  
!3\$XK]5ZT  
M d8(P23hS  
public class TestMethod { sC.r$K+k5  
`9gV8u  
>B=s+ }/ME  
public TestMethod() {MyI3mvA  
{ ///xx/weblogic60b2_win.exe IG{Me  
try{ f6Lc"b3s1  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #5kclu%L$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gqc6]{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); oylQCbT   
fileFetch.start(); :zq Un&k&  
} /U0Hk>$~(  
catch(Exception e){e.printStackTrace ();} |)" y  
^suQ7#g  
+P Dk>PdEt  
} RAk"C!&^m  
H V-;? 5  
I8% -ii  
public static void main(String[] args) WTM  
{ Pk;yn;  
new TestMethod();  7U1 M;@y  
} ,4`Vl<6  
} Y .cjEeL@  
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