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http断点续传简单实现(java)

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/* ?D8 +wj  
**SiteFileFetch.java 2ms@CQy(00  
*/ uFl19  
package NetFox; b<1+q{0r  
import java.io.*; IyJHKDFk  
import java.net.*; nlsif  
~]LkQQ'  
8\])p sb9  
public class SiteFileFetch extends Thread { &8R !`uh1  
:,[=g$CT:  
d]!`II  
SiteInfoBean siteInfoBean = null; //文件信息Bean 5?M d  
long[] nStartPos; //开始位置 ^p}|""\j  
long[] nEndPos; //结束位置 SoPiEq  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N:nhS3N<L  
long nFileLength; //文件长度 $7 FT0?kG  
boolean bFirst = true; //是否第一次取文件 G>>TB{}  
boolean bStop = false; //停止标志 &w7Ev21  
File tmpFile; //文件下载的临时信息 *Tyr  
DataOutputStream output; //输出到文件的输出流  66 @#V  
I`-N]sf^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  @& fAR2  
public SiteFileFetch(SiteInfoBean bean) throws IOException ?Q#yf8  
{ Q-7C'|  
siteInfoBean = bean; j,@@[{tu  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); LUN"p#1  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -Mx\W|YK  
if(tmpFile.exists ()) wu53e= /  
{ YOE!+MiO  
bFirst = false; GX-V|hLaGX  
read_nPos(); oTLA&dy@  
} .m/$ku{/J  
else `j)S7KN  
{ #ssSs]zl  
nStartPos = new long[bean.getNSplitter()]; jS<(O o  
nEndPos = new long[bean.getNSplitter()]; %f'mW2  
} (]gd$BgD  
:+*q,lX8  
TVs#,  
3I):W9$Qp  
} eF=cMC  
XMpa87\  
& c V$`L  
public void run() , tb\^  
{ DITo.PU  
//获得文件长度 bpp{Z1/4  
//分割文件 Y5,[udF:O  
//实例FileSplitterFetch ":!7R<t  
//启动FileSplitterFetch线程 (RBzpAiH  
//等待子线程返回 ^T&@(|o  
try{ AAW])c`.  
if(bFirst) [QZ g=."  
{ PqDffZ^z  
nFileLength = getFileSize(); i&_&4  
if(nFileLength == -1)  TG^?J`  
{ l>){cI/D#  
System.err.println("File Length is not known!"); -'%>Fon  
} F)n^pT  
else if(nFileLength == -2) g:rjt1w`D  
{ F :p9y_W  
System.err.println("File is not access!"); =&~7Q"  
} d":GsI?3  
else U_[<,JE  
{ l2Pry'3  
for(int i=0;i<nStartPos.length;i++) aP&bW))CI  
{ 8gn12._x  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); orON)S ks  
} qSA]61U&  
for(int i=0;i<nEndPos.length-1;i++) l.nd Wv  
{ o7i>D6^^  
nEndPos = nStartPos[i+1]; :f_fp(T  
} xmXuBp:M(R  
nEndPos[nEndPos.length-1] = nFileLength; w _ONy9  
} bo|3sN+D  
} xm$-:N0q  
9Rd& Jq^  
UI%Z`.&  
//启动子线程 $s]vZ(H  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M)6iYA%$  
for(int i=0;i<nStartPos.length;i++) B9(@ .  
{ ic;M=dsh:  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OC=g 1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zN3b`K. i  
nStartPos,nEndPos,i); L'L[Vpx  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); euiP<[|h=  
fileSplitterFetch.start(); -~] q?k?  
} j/p1/sJ[y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PX/7:D?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %iR"eEE  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fK{m7?V  
nEndPos = " + nFileLength); Em ;2fh  
// fileSplitterFetch[nPos.length-1].start(); )eD9H*mq  
(J 1:J  
GTuxMg`  
//等待子线程结束 f Hd|tl  
//int count = 0; VS jt|F)t  
//是否结束while循环 (|9t+KP  
boolean breakWhile = false; G$mAyK:  
/P%OXn$i/  
5_7y1  
while(!bStop) ISHzlEY  
{ fW=vN0Z  
write_nPos(); K 7 OIT2-  
Utility.sleep(500); F87/p  
breakWhile = true; 7SJR_G6,{  
Z_;! f}X  
8}K^o>J&K  
for(int i=0;i<nStartPos.length;i++) )lZoXt_3  
{ Rn$[P.||  
if(!fileSplitterFetch.bDownOver) r t0_[i  
{ l=PZlH y1G  
breakWhile = false; 0PD=/fh[  
break; nq5qUErew  
} 6^e}^~|  
} 10d.&vNw  
if(breakWhile) IhjZ{oV/@  
break; *$Z,kZ^^  
#IR,KX3]A  
6o d^+>U  
//count++; PC!g?6J  
//if(count>4) ^D8~s;?  
// siteStop(); 1I?`3N  
} 2h:{6Gq8  
R8-=N+hX  
?[<#>,W  
System.err.println("文件下载结束!"); yu>)[|-  
} SA?lDRF  
catch(Exception e){e.printStackTrace ();} PH$C."Vv  
} +Ly@5y"  
19b@QgfWpb  
?DGg.2f  
//获得文件长度 QpD- %gN  
public long getFileSize() HtV8=.^  
{ C2{*m{ D  
int nFileLength = -1; _9C,N2a{C  
try{ m+Kl   
URL url = new URL(siteInfoBean.getSSiteURL()); (YM2Cv{4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6Ts[NXa  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1ixBwnp?  
}qT{" *SC  
MY}/h@  
int responseCode=httpConnection.getResponseCode(); A{p_I<  
if(responseCode>=400) I(H9-!&  
{ Cto>~pV  
processErrorCode(responseCode); c] -  
return -2; //-2 represent access is error +ib&6IU  
} GL%)s?   
h S)lQl:^  
#&X5Di[A  
String sHeader; U"RA*|  
,N1pww?  
E7q,6f3@r  
for(int i=1;;i++) N[A9J7}_R  
{ ,bzC| AK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {)(Mkm +d  
//Utility.log(in.readLine()); Re+oCJ  
sHeader=httpConnection.getHeaderFieldKey(i); Kr?<7vMT5  
if(sHeader!=null) ~BiLzT1,  
{ Gz52^O :  
if(sHeader.equals("Content-Length")) iG#9 2e4  
{ p:V1VHT,  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M`n0 q y  
break; }kG>6_p?  
} D#P]tt.Z   
} R"j<C13;%  
else CG;+Z-"X  
break; g:Q:cSg<  
} {n&GZG"f  
} Id1de>:;  
catch(IOException e){e.printStackTrace ();} 9k \M<jA  
catch(Exception e){e.printStackTrace ();} *cZ7?  
!mmSF1f  
Tm$8\c4V:*  
Utility.log(nFileLength); }@"v7X $  
v"o_V|  
ep4?;Qmho  
return nFileLength; W[R`],x`  
} Vqcw2  
* mH&Gn1  
r KYQ 8T  
//保存下载信息(文件指针位置) &@FufpPw/  
private void write_nPos() lL'Bop@  
{ <Sr:pm  
try{ B}nT>Ub  
output = new DataOutputStream(new FileOutputStream(tmpFile)); KrR`A(=WL  
output.writeInt(nStartPos.length); LP !d|X  
for(int i=0;i<nStartPos.length;i++) 3?D{iMRM  
{ m&yHtnt  
// output.writeLong(nPos); fw VI%0C@  
output.writeLong(fileSplitterFetch.nStartPos); "!_vQ^y  
output.writeLong(fileSplitterFetch.nEndPos); R;pIi/yDRe  
} BNe>Lko  
output.close(); $&!|G-0'  
} <*+[E!oi  
catch(IOException e){e.printStackTrace ();} ~k%XW$cV  
catch(Exception e){e.printStackTrace ();} ayh235>a(  
} -BSO$'{7  
b6xz\zCL  
K:A:3~I!NW  
//读取保存的下载信息(文件指针位置) "_2;+@+  
private void read_nPos() M)U)Sc zHO  
{ *2fJdY  
try{ (&u'S+  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rp^:{6O  
int nCount = input.readInt(); re,}}'  
nStartPos = new long[nCount]; q6b&b^r+H  
nEndPos = new long[nCount]; B`gH({U  
for(int i=0;i<nStartPos.length;i++) I2krxLPd  
{ D^a(|L3;  
nStartPos = input.readLong(); :wEy""*N0  
nEndPos = input.readLong(); HYG1BfEaW  
} &-w.rF@  
input.close(); ]q"y P 0  
} wz{c;v\J^  
catch(IOException e){e.printStackTrace ();} C4GkFD   
catch(Exception e){e.printStackTrace ();} r i)`e  
} Ms5R7<O.7  
_ 2)QL  
?o`:V|<v  
private void processErrorCode(int nErrorCode) R](cko=  
{ =Ot_P7'5gv  
System.err.println("Error Code : " + nErrorCode); Gx4{ 9  
} ;U$Rd,T4S  
p>f ?Rw_  
z_=V6MDM  
//停止文件下载 )| |CU]"b?  
public void siteStop() H: ;XU  
{ $Yp.BE<}  
bStop = true; U(Bmffn4Z  
for(int i=0;i<nStartPos.length;i++) 2Q7X"ek~[  
fileSplitterFetch.splitterStop(); a]Y9;(  
2<@g *  
 -PU.Uw]  
} ` @lNt}  
} :6Tv4ZUvcG  
//负责部分文件的抓取 &;`E3$>  
**FileSplitterFetch.java u.*}'C>^^v  
*/ 4)>S3Yr  
package NetFox; KV-h~C  
OT$++cj^  
\KS.A 4  
import java.io.*; qq_ZkU@xg  
import java.net.*; O4:_c-V2  
uRYq.`v,  
5iI(A'R[7  
public class FileSplitterFetch extends Thread { j,SZJ{ebXg  
yqtaQ0F~  
a8G<x <  
String sURL; //File URL UI'fzlB  
long nStartPos; //File Snippet Start Position Ino]::ZJ/  
long nEndPos; //File Snippet End Position '1fyBU  
int nThreadID; //Thread's ID @,}tY ?>a  
boolean bDownOver = false; //Downing is over M ac?HI  
boolean bStop = false; //Stop identical G1*,~1i  
FileAccessI fileAccessI = null; //File Access interface .>~er?-  
U_.}V  
m8G/;V[x  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \rO!lvX  
{ +\u\BJ!LAJ  
this.sURL = sURL; f! )yE`4-  
this.nStartPos = nStart; 'i:lV'  
this.nEndPos = nEnd; 86!$<!I  
nThreadID = id; $ER9u2  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F-M)6&T  
} 'H4?V  
B2KBJ4rI[1  
FFe{=H,=  
public void run()  p: eaZ  
{ "q!*RO'a  
while(nStartPos < nEndPos && !bStop) l8 $.k5X  
{ \qlz<   
vlipB}  
c/:k|x  
try{ \m1^sFMZ  
URL url = new URL(sURL); d2)]6)z6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U[OUIXUi  
httpConnection.setRequestProperty("User-Agent","NetFox"); q}0I`$MU  
String sProperty = "bytes="+nStartPos+"-"; B-"F67:  
httpConnection.setRequestProperty("RANGE",sProperty); +(z[8BJl  
Utility.log(sProperty); YfMs~}h,  
ue4 {h  
#?eMEws  
InputStream input = httpConnection.getInputStream(); dWe%6s;   
//logResponseHead(httpConnection); g!r) yzK  
PnB2a'(^@?  
rW_cLdh]#  
byte[] b = new byte[1024]; %$Xt1ub6(  
int nRead; <b\8<mTr  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NS TO\36  
{ AxF$7J(  
nStartPos += fileAccessI.write(b,0,nRead); oIMS >&  
//if(nThreadID == 1) (H:A|Lw  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fF=tT C  
} ]{#Xcqx  
?YDMl  
1CM 8P3  
Utility.log("Thread " + nThreadID + " is over!"); )q\6pO@  
bDownOver = true; KoWG:~>|  
//nPos = fileAccessI.write (b,0,nRead); #`l&HV   
} I3izLi  
catch(Exception e){e.printStackTrace ();} +"JWsD(C(  
} 4d}n0b\d  
} '<*%<J{(  
_JA)""l%  
+_gA"I  
//打印回应的头信息 gS`Z>+V5!c  
public void logResponseHead(HttpURLConnection con) G `B=:s]  
{ cWo__EE  
for(int i=1;;i++) Y?zo")  
{ <Lt"e8Z>x  
String header=con.getHeaderFieldKey(i); tK'9%yA\  
if(header!=null) qSD3]Dv"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *,*XOd:3TL  
Utility.log(header+" : "+con.getHeaderField(header)); hx/A215L  
else b^()[4M;  
break; PL!dkaD^y>  
} =4U$9jo!;  
} ,JTyOBB<I  
"A5z!6T{  
L'"c;FF02i  
public void splitterStop() x&m(h1h  
{ $(08!U  
bStop = true; mv`b3 $  
} nPl,qcyY  
?P#\ CW  
%|f@WxNrU  
} ~x@V"rxGw  
F[F  NtZ  
0;*[}M]Z  
/* /q7$"wP  
**FileAccess.java >?G!>kw  
*//文件访问(定位,写) ljz=u;O)  
package NetFox; EU'rdG*t/R  
import java.io.*; k)y<iHR_o  
A1z<2.R  
QA)"3g   
public class FileAccessI implements Serializable{ nrXKS&6  
"GJ.`Hj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YB^m!A),I[  
RandomAccessFile oSavedFile; 6lkCLH  
long nPos; 'P4V_VMK  
9i{(GO  
:b_hF  
public FileAccessI() throws IOException pL>Yx>  
{ z8)&ekG  
this("",0); 8= 82x  
} =*>.z@WQ  
eu$"GbqY  
2 '$nz  
public FileAccessI(String sName,long nPos) throws IOException rg 0u#-  
{ {!wd5C@  
oSavedFile = new RandomAccessFile(sName,"rw"); \8vZZt  
this.nPos = nPos; M9(lxu y1  
oSavedFile.seek(nPos); "+ k}#<P4\  
} fi&>;0?7  
i1]}Q$  
62G %.'7  
public synchronized int write(byte[] b,int nStart,int nLen) AI,E9  
{ 300[2}Y]  
int n = -1; 9+.3GRt7  
try{ /c4$m3?]  
oSavedFile.write(b,nStart,nLen); p!<PRms@  
n = nLen; )oM% N  
} uaCI2I  
catch(IOException e) c]qh)F$s8  
{ :3J`+V}9;  
e.printStackTrace (); r/0AM}[!*j  
} 2n#H%&^?a  
}/IP\1bG  
(hRg0Z=  
return n; 1 .o0"  
} sqRvnCD!  
,ZO?D|M1  
XB:E<I'q!3  
} 4s"x}c">F  
' 8Q }pp`  
NpbZt;%t  
/* fl4'dv  
**SiteInfoBean.java R4zOiBi'B  
*/ 55,2eg#{O  
package NetFox; %/!f^PIwX  
!RjC0,  
,Hp7`I>/  
public class SiteInfoBean { r CUs  
}We-sZ/w7r  
3-[+g}kak?  
private String sSiteURL; //Site's URL 1&Mpx!K*T  
private String sFilePath; //Saved File's Path 58`Dcx,yJ  
private String sFileName; //Saved File's Name %/_E8GE  
private int nSplitter; //Count of Splited Downloading File +vV?[e  
0[8uuqV[cB  
n*#HokX  
public SiteInfoBean() _U,Hi?b"$}  
{//nSplitter的缺省值为5 Wi~?2-!  
//default value of nSplitter is 5 }b{7+ + Ah  
this("","","",5); UA4MtTp`  
} 9tmnx')_  
GK3cQw  
:01B)~^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @Yw42`> !s  
{ e{^lD.E  
sSiteURL= sURL; '?3(&  
sFilePath = sPath; VmXXj6l&  
sFileName = sName; -f?,%6(1  
this.nSplitter = nSpiltter; 1].m4vC  
3S%/>)k  
TpHzf3.I  
} p>+Q6o9O  
EQ"+G[j~x  
Z8f?uF  
public String getSSiteURL() zP|^@Homk  
{ r*FAUb`bG  
return sSiteURL; \(zUI  
} ^^YP kh6sS  
~ET XXu${I  
&F*eo`o}6  
public void setSSiteURL(String value) (SA^> r  
{ 1DH P5q  
sSiteURL = value; dMI G2log  
} ~Ds3 -#mMy  
{qs>yQ6a:-  
3aJYl3:0B  
public String getSFilePath() }5Km \OI  
{ @jZ1WHS_a  
return sFilePath; f'Oj01[  
} 9j 0o)]  
ZJ/K MW  
Nkn2\ w  
public void setSFilePath(String value) #TB 3|=  
{ e=_Ng j)  
sFilePath = value; jFI`CA6P  
} s;[WN.  
L9!\\U  
DIkf#}  
public String getSFileName() fW=eB'Sl  
{ 7IrH(~Fo  
return sFileName; 3A.lS+P1  
} :+8qtIytKX  
{?r5~ T`2  
Sj v iH  
public void setSFileName(String value)  e `K{  
{ +{%)}?F  
sFileName = value; R^INl@(O  
} #K/95!)  
ROO@EQ#`Z  
E+$D$a  
public int getNSplitter() vLGnLpt  
{ z]&?}o  
return nSplitter; g#G ]}8C  
} ezS@`_pR;  
{9cjitl  
zT>BC}~.b  
public void setNSplitter(int nCount) lx> ."rW  
{ E=]|v+#~  
nSplitter = nCount; ss`Sl$  
} vb9C&#  
}  k =O  
'*<I<? z;  
_s}`ohKvD  
/* .d?LRf  
**Utility.java O0eM*~zI  
*/ }:!X@C~  
package NetFox; k[y^7, r  
!&5*H06  
| 3`8$-  
public class Utility { T`GiM%R;g  
1-|aeJ  
mri g5{  
public Utility() Mt@Ma ]!  
{ WYIv&h<h"  
+fQJ#?N2n  
2AEVBkF;M  
} ZzxWKIE'c  
eYevj[c;  
//线程睡眠 YdN]Tqc  
public static void sleep(int nSecond) Zg|l:^E  
{ DHZ`y[&}|N  
try{ S F da?>  
Thread.sleep(nSecond); v4XEp   
} ClNuO  
catch(Exception e) QZuKM'D+  
{ h05<1>?|  
e.printStackTrace (); 20I/En  
} e`Co ='  
} Of}C.N8  
RrdLh z2N  
//日志 OP\L  
public static void log(String sMsg) kM(m$Oo.  
{ )4> 7X)j>  
System.err.println(sMsg); LCuz_LTFq{  
} yI^7sf7k  
oVW>PEgB-  
\9`.jB~<  
public static void log(int sMsg) *Rxn3tR7  
{ Rr}m(e=  
System.err.println(sMsg); gMp' S  
} 3 rR1/\  
} `$q0fTz  
qqys`.  
9_ZGb"(Lj  
/* \ _?d?:#RD  
**TestMethod.java T1'\!6_5  
*/ 5=R]1YI~$  
package NetFox;  GInw7  
Q 9E.AN  
&y7xL-xP  
public class TestMethod { +k[w)7Q  
ls~9qkAyLx  
 ;v/un  
public TestMethod() !OMCsUZ  
{ ///xx/weblogic60b2_win.exe ~wO-Hgd  
try{ p|@#IoA/e  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N|3#pHm@  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }Kn l  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7k00lKA\w  
fileFetch.start(); @uanej0q7  
} |*Oi:)qt  
catch(Exception e){e.printStackTrace ();} p7HLSB2Rp  
U+C ^"[B  
DO( 3hIj  
} :6/$/`I0W  
^;tB,7:*V  
lS#^v#uS  
public static void main(String[] args) -!K&\hEjj  
{ =^\?{oV  
new TestMethod(); %jHe_8=o  
} 1U?5/Ja  
} H!>>|6OPF  
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