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http断点续传简单实现(java)

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/* c| %5SA  
**SiteFileFetch.java ]xf89[;0  
*/ _9oKW;7f7  
package NetFox; 6I[*p0j5  
import java.io.*; mI2Gs) SO  
import java.net.*; |A4B4/!  
t{,$?}  
2NFk#_9e~  
public class SiteFileFetch extends Thread { U["<f`z4\  
3 EAr=E]  
JP!e'oWxi  
SiteInfoBean siteInfoBean = null; //文件信息Bean ln<[CgV8  
long[] nStartPos; //开始位置 /5%'q~  
long[] nEndPos; //结束位置 2k!uk6  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &[`2 4Db  
long nFileLength; //文件长度 Wz^;:6F  
boolean bFirst = true; //是否第一次取文件 oD%n}  
boolean bStop = false; //停止标志 QeY+imM  
File tmpFile; //文件下载的临时信息 0ytAn+/"x  
DataOutputStream output; //输出到文件的输出流 x~'_;>]r_  
[\F:NLjiUy  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 4][VK/v+  
public SiteFileFetch(SiteInfoBean bean) throws IOException yS)k"XNb  
{ B^19![v3T  
siteInfoBean = bean; Zn1((J7  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));  H#F"n"~$  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); W}F~vx.  
if(tmpFile.exists ()) wz+mFf  
{ :WH{wm|  
bFirst = false; E.yFCaL  
read_nPos(); 6oKlr,.  
} iMry0z  
else | {zka.sJ  
{ `B?+1Gv  
nStartPos = new long[bean.getNSplitter()]; @MQfeM-@  
nEndPos = new long[bean.getNSplitter()]; :~s"]*y  
} y**L^uvr  
Q3r]T.].h  
};2Lrz9<  
!}A`6z  
} 4P C'7V=S  
\>T1&JT  
]Y & 2&  
public void run() &2@"zD  
{ zt((TD2  
//获得文件长度 "= s dn  
//分割文件 d+Mogku2  
//实例FileSplitterFetch *{JD= ua  
//启动FileSplitterFetch线程 W9Us I  
//等待子线程返回 2+|r*2_glo  
try{ Gj#BG49g2  
if(bFirst) )p!") :'fv  
{ "6e3Mj\  
nFileLength = getFileSize(); 7F~Jz*,B*W  
if(nFileLength == -1) q q^[(n  
{ u 'ng'j'  
System.err.println("File Length is not known!"); YC{7;=P f  
} Vg (p_k45`  
else if(nFileLength == -2) @8YuMD;  
{ 9( &$Gwi  
System.err.println("File is not access!"); ,gP;XRe1  
} .>`7d=KT  
else EZQ!~  
{ q9(O=7O]-  
for(int i=0;i<nStartPos.length;i++) E?0RR'  
{ Nf~B 1vkp  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?#5)TAW  
} 2}{[ J  
for(int i=0;i<nEndPos.length-1;i++) }k1[Fc|  
{ B^1jd!m  
nEndPos = nStartPos[i+1]; _qit$#wK;  
} { F0"U=  
nEndPos[nEndPos.length-1] = nFileLength; 6{Bvl[mhI  
} M~sP|Ha"+  
} gi A(VUwI>  
;?o"{mbb  
oxCfSA  
//启动子线程 a`||ePb|W~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y9:o];/  
for(int i=0;i<nStartPos.length;i++) fQU_A  
{ a.<!>o<t:  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '?|.#D#-c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [o'}R`5)  
nStartPos,nEndPos,i); +w?1<Z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tq6@ 1j6p  
fileSplitterFetch.start(); HV3D$~gF  
} wZ8LY;  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  `Q^Vm3h  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k/xNqN(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (w'k\y  
nEndPos = " + nFileLength); [s!cc:JR  
// fileSplitterFetch[nPos.length-1].start(); )o_$AbPt  
@0:mP  
}>Lz\.Z/+[  
//等待子线程结束 ku5g`ho  
//int count = 0; "%t !+E>nr  
//是否结束while循环 g.EKdvY"%H  
boolean breakWhile = false; 1 pzd  
qr/N?,  
\AR3DDm  
while(!bStop) 6 dCqS  
{ iu,Bmf^oD  
write_nPos(); 2wh{[Q2f  
Utility.sleep(500); 5al44[  
breakWhile = true; Ks7kaX  
 hWu#}iN  
-E!V;Tgc%U  
for(int i=0;i<nStartPos.length;i++) h 9{'w  
{ `=foB-(zt  
if(!fileSplitterFetch.bDownOver) |B*`%7{+  
{ CV,[x[L# {  
breakWhile = false; qoD M!~  
break; j[1^#kE  
} "2/VDB4!FG  
} 1<9m^9_ro  
if(breakWhile) -Kf'02  
break; +%RXV ~  
`!T6#6h  
|c>A3 P$=B  
//count++; )6zwprH!  
//if(count>4) HaamLu  
// siteStop(); d3C*]|gQ  
} QO~ TuC  
z//6yr  
=mk7'A>l  
System.err.println("文件下载结束!"); 3?(||h{  
} `S7${0e  
catch(Exception e){e.printStackTrace ();} ?+#E&F  
} ?3i-wpzMp  
QPa&kl  
sXSZ#@u,WN  
//获得文件长度 pKSVT  
public long getFileSize() Ec]cCLB  
{ <tTn$<b  
int nFileLength = -1; xF{<-b  
try{ j&?NE1D>I  
URL url = new URL(siteInfoBean.getSSiteURL()); 86@@j*c(@k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )Nq$~aAm  
httpConnection.setRequestProperty("User-Agent","NetFox"); yyHr. C  
0?j+d8*  
BT+ws@|[  
int responseCode=httpConnection.getResponseCode(); 'x10\Q65[  
if(responseCode>=400) \bb,gRfP  
{ !$+J7\& 7p  
processErrorCode(responseCode); dDk<J;~jGJ  
return -2; //-2 represent access is error Lp/]iZ@  
} S,v9\wN.  
NC2PW+(  
*%cI,}%   
String sHeader; P z+8u&~p  
A|@d4+  
2S8/ lsB  
for(int i=1;;i++) nmN6RGx  
{ 'bg%9}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9W7H",wR  
//Utility.log(in.readLine()); GRj{*zs  
sHeader=httpConnection.getHeaderFieldKey(i); gGdZ}9  
if(sHeader!=null) 'gE_xn7j  
{ G";yqG  
if(sHeader.equals("Content-Length")) _B|g)Rdv  
{ #,qikKjt2  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TO)wjF_  
break; M|`%4vk>  
} ]?Ru~N}  
} *pv hkJ g(  
else sM~|}|p  
break; FUm-Fp  
} y#Ch /Jg?|  
} .x1EdfHed/  
catch(IOException e){e.printStackTrace ();} >UuLSF}  
catch(Exception e){e.printStackTrace ();} uBs[[9je(  
~GS`@IU}  
?P`]^#  
Utility.log(nFileLength); te'<xfG  
4aZsz,=  
e}}xZ%$4|  
return nFileLength; -]PW\}w1  
} +3t(kQ  
Md_\9G .e  
zYj8\iER  
//保存下载信息(文件指针位置) D x Vt  
private void write_nPos() ;LH?Qu;e  
{ 4F 8`5)RM  
try{  c:~o e  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \aT._'=M+  
output.writeInt(nStartPos.length); /)y~%0  
for(int i=0;i<nStartPos.length;i++) /{1xpR  
{ '&T4ryq3"  
// output.writeLong(nPos); lTdYPqMi  
output.writeLong(fileSplitterFetch.nStartPos); ">voi$Kzey  
output.writeLong(fileSplitterFetch.nEndPos); oc-7gz)  
} hgKs[ySo,3  
output.close(); JCaT^KLz  
} "Rs^0iT7>  
catch(IOException e){e.printStackTrace ();} P67r+P,  
catch(Exception e){e.printStackTrace ();} !Nl"y'B|  
} Q.6pmaXrb  
Ctt{j'-[  
?^IM2}(p  
//读取保存的下载信息(文件指针位置) g[@]OsX   
private void read_nPos() hlkf|H  
{ E9226  
try{ I[<C)IG  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 35jP</  
int nCount = input.readInt(); sOLo[5y'  
nStartPos = new long[nCount]; R`>E_SY  
nEndPos = new long[nCount]; [N#2uo  
for(int i=0;i<nStartPos.length;i++) kRE^G*?  
{ UXa3>q>  
nStartPos = input.readLong(); 94|BSxc  
nEndPos = input.readLong(); n&[U/`o  
} I%*o7"  
input.close(); +5);"71  
} iAWPE`u4  
catch(IOException e){e.printStackTrace ();} ~"}-cl,  
catch(Exception e){e.printStackTrace ();} {v]A`u)  
} rmR7^Ycv/  
a50{gb#  
=`vUWONn  
private void processErrorCode(int nErrorCode) &sWq SS  
{ Fv5@-&y$W  
System.err.println("Error Code : " + nErrorCode); XF{}St~(  
} UO<%|{ W+  
='OPU5(;O  
a*S4rq@  
//停止文件下载 R[Kyq|UyVr  
public void siteStop() KH2a 2  
{ ^i#q{@g  
bStop = true; cD2}EqZ 9  
for(int i=0;i<nStartPos.length;i++) o $p*C  
fileSplitterFetch.splitterStop(); 0xC{Lf&  
b^5rV5d  
MWsBZJRr  
} 7ktf =Y  
} /_w oCLwQ#  
//负责部分文件的抓取 v*l1"0$  
**FileSplitterFetch.java o& $Fc8bH  
*/ 0ltq~K  
package NetFox; ?OvtR:hC  
X )g <F  
M_UhFY='  
import java.io.*; OES+BXGX  
import java.net.*; i>q]U:U  
0P\)L`cG  
{o5E#<)  
public class FileSplitterFetch extends Thread { Ck(D: % ~s  
!lL21C6g+  
E@P8-x'i  
String sURL; //File URL -5d8j<,  
long nStartPos; //File Snippet Start Position d^WVWk K  
long nEndPos; //File Snippet End Position zn>*^h0B  
int nThreadID; //Thread's ID Ry[VEn>C1  
boolean bDownOver = false; //Downing is over x@Z?DS$)  
boolean bStop = false; //Stop identical =f{V<i~q  
FileAccessI fileAccessI = null; //File Access interface f(7 /  
!}Cd_tj6  
t#}/VnSQ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &d9tR\}  
{ p^7ZFUP  
this.sURL = sURL; GZ UDI#  
this.nStartPos = nStart; +;pdG[N  
this.nEndPos = nEnd; x(5>f9bb  
nThreadID = id; UFm E`|le  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~%k<N/B  
} VGA?B@  
q9yY%  
"+r8izB  
public void run() 7oh6G  
{  ]6W#P7  
while(nStartPos < nEndPos && !bStop) B.;/N220P  
{ -`FTWH  
>j_,3{eJ  
TR5"K{WDx  
try{ :_i1)4[!  
URL url = new URL(sURL); j!qO[CJJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^'*9,.ltd  
httpConnection.setRequestProperty("User-Agent","NetFox"); 70mQ{YNN  
String sProperty = "bytes="+nStartPos+"-"; S;a{wYF6v  
httpConnection.setRequestProperty("RANGE",sProperty); \O^b|0zc  
Utility.log(sProperty); D%Hz'G0|  
u==bLl=$  
;:hyW,J  
InputStream input = httpConnection.getInputStream(); +JB. EW/  
//logResponseHead(httpConnection); 2YdMsu~  
j{0_K +B  
3 =KfNz_  
byte[] b = new byte[1024]; q[ ] "`?  
int nRead; $j)Er.!9|R  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %f#3;tpC8  
{ a7)q^;:O  
nStartPos += fileAccessI.write(b,0,nRead); kNMhMEez  
//if(nThreadID == 1) Se%FqI  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j^"Z^TEBT  
} mBhG"0:  
qi.|oL9p  
;mu9;ixZ  
Utility.log("Thread " + nThreadID + " is over!"); cx&jnF#$  
bDownOver = true; Gyw@+(l  
//nPos = fileAccessI.write (b,0,nRead); `QC{}Oo^  
} n1a;vE{!  
catch(Exception e){e.printStackTrace ();} ~*ZB2  
} L8Z[Ly+_  
} 8tK8|t5+  
L/1?PM  
h3h2 KqM'  
//打印回应的头信息  Ma0_!|i  
public void logResponseHead(HttpURLConnection con) 'bN\bbR  
{ l=`)yc.  
for(int i=1;;i++) ;l[/<J  
{ pj6Q0h)  
String header=con.getHeaderFieldKey(i); Ge8&_7  
if(header!=null) t IdH?x  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0e^j:~*  
Utility.log(header+" : "+con.getHeaderField(header)); x;# OM  
else 3o%JJIn&  
break; 3x#=@i  
} VTa?y  
} qN1(mxa.?  
R)?K+cJ%  
ja$e)  
public void splitterStop() [9u/x%f(  
{ no?TEXp*  
bStop = true; f"~+mO  
} +M/04  
-IMm#  
?<YtlqL  
} i44UqEb  
7v}4 Pl,$4  
R0(Nw7!d/[  
/* p4\%*ovQt  
**FileAccess.java &,4^LFZ W  
*//文件访问(定位,写) {d.`0v9h  
package NetFox; |Vs|&0  
import java.io.*; Ua#*kTF  
=#[_8)q  
GrGgR7eC#P  
public class FileAccessI implements Serializable{ t48(,  
i,NN"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5r.\maW  
RandomAccessFile oSavedFile; y, tA~  
long nPos; H'-Fv!l?  
7 6~x|6)  
X's-i!  
public FileAccessI() throws IOException VHsuC$3W  
{ c2Ua!p(c  
this("",0); I1=YSi;A  
} <T[%03  
6A7UW7/  
%f\ M61Z  
public FileAccessI(String sName,long nPos) throws IOException E1_FK1*V;  
{ 2mP| hp?  
oSavedFile = new RandomAccessFile(sName,"rw"); /7De .O~H  
this.nPos = nPos; =i~/.Nu&  
oSavedFile.seek(nPos); dGAthbWJ  
} l7Y^C1hM  
5m&{ f>]T  
v_J\yW'K  
public synchronized int write(byte[] b,int nStart,int nLen) o^wj_#ai$  
{ j_-$xz5-  
int n = -1; - o$S=  
try{ (k"|k  
oSavedFile.write(b,nStart,nLen); vQ^a7  
n = nLen; PorBB7iL  
} k2sb#]-/}  
catch(IOException e) H6 ( ~6Bp5  
{ B< P H7  
e.printStackTrace (); d~tG#<^`  
} M6vW}APH[n  
j)Zi4<./  
i >Hh_q;'  
return n; O?p.kf{b  
} cpz}!D  
jb$sIZ%i  
G1  %c<1Y  
} 2f]:n  
EMU~gwPR  
3!`Pv ?|o  
/* Jg/l<4,K,  
**SiteInfoBean.java  %1<No/  
*/ x-:vpv%6y  
package NetFox; h ^g"FSzP  
 7=0uG  
us\@n"  
public class SiteInfoBean { n=MdbY/k(  
I >k3X~cG  
8s-RNA>7^  
private String sSiteURL; //Site's URL Gy.<gyK9  
private String sFilePath; //Saved File's Path S;M'qwN  
private String sFileName; //Saved File's Name N*$<Kjw  
private int nSplitter; //Count of Splited Downloading File x~!B.4gT2  
]|<PV5SY3.  
V:9|9$G  
public SiteInfoBean() J4 .C"v0a  
{//nSplitter的缺省值为5 [Tby+pC  
//default value of nSplitter is 5 ~;_]U[eOL  
this("","","",5); GeWB"(t  
} E)3B)(@&P  
PvBx<i}A  
18z{d9'F   
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p<Wb^BE  
{ %h=)>5-T  
sSiteURL= sURL; kX zm  
sFilePath = sPath;  g2L  
sFileName = sName; AT}}RE@vq  
this.nSplitter = nSpiltter; 5Qd |R  
5)' _3r  
#`RY KQwB  
} =xQ 7:TB  
fs&J%ku\  
A9qCaq{  
public String getSSiteURL() ^+oi|y  
{ oF,XSd  
return sSiteURL; 9"52b 9U  
} LO[1xE9  
eW"i'\`0  
?aEBS  
public void setSSiteURL(String value) 'Y(#Yxc  
{ gP/[=:  
sSiteURL = value; %E?:9. :NJ  
} QIQB  
[6K2V:6:  
>/;\{IG Wn  
public String getSFilePath() \NhCu$'  
{ q -M&f@Il  
return sFilePath; >"jV8%!sM  
} /*`BGNkYY  
!CtY.Lp  
Ziu f<X{  
public void setSFilePath(String value) nQdNXv<(  
{ k(C?6Gfj  
sFilePath = value; [q cT?h  
} `IOp*8  
MVg`6&oH  
NLyvi,svS  
public String getSFileName() M$ep.<Z1|  
{ .{k(4_Q?I  
return sFileName; TP{lt6wws(  
} 2FD[D `n]f  
tBtJRi(  
nT` NfN  
public void setSFileName(String value) I{<6GIU+  
{ kQC>8"  
sFileName = value; B}X   C  
} N?Mmv|  
7U:,:=  
7loCb4Hv  
public int getNSplitter() BnvUPDT&  
{ VD/Wl2DK  
return nSplitter; )wP0U{7?v  
} }r]WB)_w  
r/HKxXT  
s#`%c({U|  
public void setNSplitter(int nCount) SW (7!`  
{ t!c8 c^HR  
nSplitter = nCount; aQCbRS6  
} vY *p][$  
} n} GIf&  
:>nk63V (  
ioi0^aM  
/* l<PGUm:_  
**Utility.java THJ KuWy  
*/ &YO5N4X~o  
package NetFox; j8zh^q  
-?e~dLu  
ABNsi$]r0  
public class Utility { XtT;UBE  
Bh:AY@k  
j8?$Hk  
public Utility() TUJ]u2J8?  
{ W2|*:<Jt  
CWE jX-  
eM/|"^%  
} C@pDX>~2=b  
-4,qAnuMx  
//线程睡眠 nuw90=qj!]  
public static void sleep(int nSecond) Id]WKL:  
{ SjKIn-  
try{ 3 C=nC  
Thread.sleep(nSecond); -}{\C]%  
} cmt3ceCb  
catch(Exception e) .Y_RI&B!L  
{ tH 5f;mY,  
e.printStackTrace (); \@pl:Os  
} [4kx59J3b  
} :|<D(YA  
lcJ`OLG  
//日志 hOfd<k\A  
public static void log(String sMsg) fB1JU1  
{ ]j*o&6cQf  
System.err.println(sMsg); zVxiCyU  
} [H0jDbN  
tFwQ /  
\b.2f+;3  
public static void log(int sMsg) "M7ry9dDH  
{ Lr)h>j6\  
System.err.println(sMsg); L]9!-E  
} m4 E 6L  
} s[nOB0  
1:My8  
cIl^5eE^Pq  
/* `!qWHm6I*  
**TestMethod.java ;Zj Qy,H%  
*/ RduA0@g0  
package NetFox; (d^pYPr{  
~S|Vd  
,U>g LTS  
public class TestMethod { #$jAGt3^BT  
[+{ ot   
/Ia=/Jj7N  
public TestMethod() n+zXt?{u  
{ ///xx/weblogic60b2_win.exe TnM}|~V  
try{ +/\.%S/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =!U{vT  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VQPq+78  
SiteFileFetch fileFetch = new SiteFileFetch(bean); w#Nn(!VR  
fileFetch.start(); ~Ufcy{x#  
} &_" 3~:N8k  
catch(Exception e){e.printStackTrace ();} \5s!lv*&  
p]!,Bo ZL  
t=XiSj\n  
} l3-Ksw U  
LrF'Hd=O  
?e3q0Lg3 |  
public static void main(String[] args) L}>9@?;GW  
{ 4DuZF -y  
new TestMethod(); En5Bsz !  
} m|24)%Vj;=  
} t~5>PS  
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