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http断点续传简单实现(java)

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/* )0xEI  
**SiteFileFetch.java NzuH&o][  
*/ R22P ol  
package NetFox; e \ rb  
import java.io.*; Ax"I$6n>  
import java.net.*; VKXZA2<?'  
32ae? d  
ZeY kZzN  
public class SiteFileFetch extends Thread { \J?5K l[*c  
}%I)bU  
O.~@V(7ah  
SiteInfoBean siteInfoBean = null; //文件信息Bean um$K^  
long[] nStartPos; //开始位置 _I}rQfPJ  
long[] nEndPos; //结束位置 (8/Qt\3jv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 )XAD#GYM  
long nFileLength; //文件长度 JdW:%,sv  
boolean bFirst = true; //是否第一次取文件 @C fxPA  
boolean bStop = false; //停止标志 kVu-,OU  
File tmpFile; //文件下载的临时信息 "7tEk<x  
DataOutputStream output; //输出到文件的输出流 POCFT0R}  
h2C1'+Q{9  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) W9ewj:4\0  
public SiteFileFetch(SiteInfoBean bean) throws IOException ,0R2k `m!  
{ 4$<-3IP,  
siteInfoBean = bean; %aeQL;# V  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); h f1f  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); KU}HVM{  
if(tmpFile.exists ()) 7VwLyy  
{ )!``P?3?  
bFirst = false; I=3e@aTZ,  
read_nPos(); e!(0y)*  
} jW-j+ WGSM  
else \Ow-o0  
{ &G>EBKn\2`  
nStartPos = new long[bean.getNSplitter()]; wGC)gW  
nEndPos = new long[bean.getNSplitter()]; $N#f)8v  
} *0,?QS-a  
c=T^)~$$  
)A4WK+yD$z  
$I7/FZP  
} hC.7Z]  
%q@eCN  
?wR;"  
public void run() i7[CqObzc  
{ <(Wa8PY2(  
//获得文件长度 a9q68  
//分割文件 X]Emz"   
//实例FileSplitterFetch k]Y#-Q1p~  
//启动FileSplitterFetch线程 {da Nw>TH  
//等待子线程返回 d/GP.d  
try{ }Vpr7_  
if(bFirst) Lj$yGdK<  
{ cf|<~7  
nFileLength = getFileSize(); KsGSs9  
if(nFileLength == -1) .Jz$)R  
{ v?yHj-  
System.err.println("File Length is not known!"); _gY so]S^B  
} WG;1[o&  
else if(nFileLength == -2) S #X$QD  
{ k})Ag7c  
System.err.println("File is not access!"); cK>5!2b  
} fz W%(.tc\  
else <v"C`cga  
{ buRXzSR  
for(int i=0;i<nStartPos.length;i++) qphN   
{ }}?L'Vby  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1{%EQhNd  
} _VR Sdr5  
for(int i=0;i<nEndPos.length-1;i++) A^JeB<, 5a  
{ | zj$p~  
nEndPos = nStartPos[i+1]; ' %OQd?MhL  
} QzIK580%t  
nEndPos[nEndPos.length-1] = nFileLength; e+=Ojo#  
} g?M\Z";  
} /40Z-'Bl=(  
nD.4c-hd$q  
g!7/iKj:  
//启动子线程 (^eSm]<  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PDX^MYoN  
for(int i=0;i<nStartPos.length;i++) 7I`e5\ u  
{ N40.GL0s  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'oHtg @  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r,i^-jv;  
nStartPos,nEndPos,i); c\.4I4uy  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <!&nyuSz  
fileSplitterFetch.start(); XN]kNJX  
} IQdiVj  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &oYX093di  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m$A|Sx&sG$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^MUtmzh  
nEndPos = " + nFileLength); hkv&Od,  
// fileSplitterFetch[nPos.length-1].start(); suaTXKjyk+  
G F,/<R#  
"sf8~P9qy  
//等待子线程结束 A;w,m{9<  
//int count = 0; L]kSj$A  
//是否结束while循环 F)lDK.  
boolean breakWhile = false; V?HC\F-  
\x)T_]Gcm  
+WK!}xZR  
while(!bStop) 2@1A,  
{ ar=uDb;  
write_nPos(); xc8MOm  
Utility.sleep(500); I 8`@Srw8  
breakWhile = true; e0+N1kY  
\8=>l?P  
+Ld4 e]  
for(int i=0;i<nStartPos.length;i++) +l2{EiQw  
{ D^I%tn=F  
if(!fileSplitterFetch.bDownOver) %Ox*?l _  
{ 6N:fq  
breakWhile = false; M2[;b+W9  
break; 7 \!t/<  
} 2ME3=C  
} U=QV^I Qm  
if(breakWhile) QW|,_u5j  
break; V3xC"maA@  
|OUr=b  
W7S`+Pq  
//count++; 41^+T<+  
//if(count>4) ((N<2G)  
// siteStop(); 6^s=25>p  
} vR3'B3y  
{2}O\A  
cc*A/lD  
System.err.println("文件下载结束!"); ; ob>$ _  
} S j)&!  
catch(Exception e){e.printStackTrace ();} #Fl "#g$  
} AwAUm 2^  
t`o-HWfS.  
{l%Of  
//获得文件长度 vtKQvQ  
public long getFileSize() {PnvQ?|Z  
{ e]'ui<`  
int nFileLength = -1; 0g,;Yzm  
try{ !0CC&8C`  
URL url = new URL(siteInfoBean.getSSiteURL()); !=3[Bm G  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z O5_n  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?"N, do  
<[@AMdS  
s% 2w&Us*  
int responseCode=httpConnection.getResponseCode(); 4`yCvPu  
if(responseCode>=400) IC{\iwO/~c  
{ 7;jwKA;k  
processErrorCode(responseCode); *8M 0h9S$  
return -2; //-2 represent access is error X9K@mX  
} szu!*wc9  
uPr'by  
zt/b S/  
String sHeader; WUm8 3"  
eY)ugq>'  
yl/-!  
for(int i=1;;i++) @e8b'w3  
{ <^c?M[ j  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Uoe;4ni  
//Utility.log(in.readLine()); !K-lO{Z^  
sHeader=httpConnection.getHeaderFieldKey(i); C#d .3t  
if(sHeader!=null) 18f!k  
{ h+<vWo}H  
if(sHeader.equals("Content-Length")) 8/F}vfKEN  
{ IL;JdIa  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  S {oW  
break; 2$?bLvk  
} <E/4/ ANN  
} y.(Yh1  
else v._Q XcE  
break; M3P\1  
} 3tzb@T  
} Q#w mS&$f  
catch(IOException e){e.printStackTrace ();} ySAkj-< /P  
catch(Exception e){e.printStackTrace ();} r@b M3V_o  
qWX%[i%  
;,2i1m0"  
Utility.log(nFileLength); N^</:R  
2[!#Xf  
tljZE)  
return nFileLength; $cjwY$6  
} cq:<,Ke  
(mbC! !>  
=h5&:?X  
//保存下载信息(文件指针位置) `o/G0~T)  
private void write_nPos() O&BNhuW2  
{ .)=T1^[hI  
try{  dpG l  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %87D(h!.I4  
output.writeInt(nStartPos.length); WXHvUiFf  
for(int i=0;i<nStartPos.length;i++) ?.Iau/  
{ DBTeV-G9~R  
// output.writeLong(nPos); UU\wP(f  
output.writeLong(fileSplitterFetch.nStartPos); %!DdjC&5*  
output.writeLong(fileSplitterFetch.nEndPos); V /i~IG`h/  
} pHKcKqB*13  
output.close(); (sM$=M<$  
} C_> WU   
catch(IOException e){e.printStackTrace ();} rtM29~c>@  
catch(Exception e){e.printStackTrace ();} pQ~Y7  
} zXX =WH  
^.3(o{g  
78M%[7Cq<i  
//读取保存的下载信息(文件指针位置) LV}Z[\?   
private void read_nPos() i ZU 1w7Z  
{ 2/o_,k  
try{ xWRkg$A  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D[jPz0  
int nCount = input.readInt(); I{nrOb1G(  
nStartPos = new long[nCount]; g \.O5H9Od  
nEndPos = new long[nCount]; OQnb^fabY  
for(int i=0;i<nStartPos.length;i++) &VPfI  
{ ZNfQM&<d  
nStartPos = input.readLong(); 7a0T]  
nEndPos = input.readLong(); t[e`wj+qz  
} cG)U01/"  
input.close(); G/ sRi wL  
} y':JUwUN  
catch(IOException e){e.printStackTrace ();} m>FP&~2  
catch(Exception e){e.printStackTrace ();}  u> @@  
} @@W-]SR  
dBm!`;r4  
\yhj{QS.k  
private void processErrorCode(int nErrorCode) @1vpkB~ w  
{ 9jI5bi)  
System.err.println("Error Code : " + nErrorCode); $O^"O Q_@  
} 3S"kw  
|.?$:D&6  
y:YJv x6&4  
//停止文件下载 `u" )*Q}  
public void siteStop() x31Jl{x8\?  
{ 06NW2A%wv  
bStop = true; wBz5_ OFVw  
for(int i=0;i<nStartPos.length;i++) JN-W`2  
fileSplitterFetch.splitterStop(); =`g@6S  
]$)U~)T iW  
]--" K{  
} mvu$  
} AP9>_0=  
//负责部分文件的抓取 ldWrv7. P  
**FileSplitterFetch.java _F`RwBOjs  
*/ 9'0v]ar  
package NetFox; vw*,_f  
ebiOR1)sN  
,&LGAa  
import java.io.*; ki ?ETC  
import java.net.*; %I#[k4,N  
ozkmZ;  
_ykT(`.#  
public class FileSplitterFetch extends Thread { 5@^['S4%8*  
J3y4 D}  
qa,i:T(w  
String sURL; //File URL IzlmcP3  
long nStartPos; //File Snippet Start Position Vi>`g{\  
long nEndPos; //File Snippet End Position <xh";seL  
int nThreadID; //Thread's ID /-Y.A<ieN8  
boolean bDownOver = false; //Downing is over <|;)iT1VeT  
boolean bStop = false; //Stop identical  %Krf,H  
FileAccessI fileAccessI = null; //File Access interface O~c\+~5M*  
Qq<+QL|  
h 6juX'V  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (3N;-   
{ Y\j5{;V  
this.sURL = sURL; QBLha']'%  
this.nStartPos = nStart; lj 2OOU{  
this.nEndPos = nEnd; Jj7he(!_1  
nThreadID = id; ]] 50c  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -op(26:W<  
} oT*qMLdn  
I5#zo,9  
:ywm4)  
public void run() a[7 Lqu  
{ 1{?5/F \ +  
while(nStartPos < nEndPos && !bStop) iJ p E`  
{ d[y(u<Vl  
 4_d'Uh&]  
frUO+  
try{ oNp(GQ@0  
URL url = new URL(sURL); '<Jqp7$dL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HBcL1wfS  
httpConnection.setRequestProperty("User-Agent","NetFox"); AZfW  
String sProperty = "bytes="+nStartPos+"-"; ?K= X[  
httpConnection.setRequestProperty("RANGE",sProperty); !c;BOCqa  
Utility.log(sProperty); ,7ZV;f 81  
yc.9CTxx  
&'oZ]}^ 0  
InputStream input = httpConnection.getInputStream(); /7uA f{  
//logResponseHead(httpConnection); %)sG 34  
-HUlB|Q8r  
0tEe $9eK@  
byte[] b = new byte[1024]; 0%"sOth  
int nRead; eY8rm  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tl^![Z  
{ {R}Kt;L:Ut  
nStartPos += fileAccessI.write(b,0,nRead); |6GDIoZ  
//if(nThreadID == 1) Hg 2Rcl  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Bp5^(s  
} O^KIB%}fu  
D\k'Eez  
UpS7>c7s  
Utility.log("Thread " + nThreadID + " is over!"); rvp#[RAaS}  
bDownOver = true; s|IC;C|  
//nPos = fileAccessI.write (b,0,nRead); 6Ej.X)~'K  
} C(}N*e1  
catch(Exception e){e.printStackTrace ();} y-lBaTE9  
} ##BfI`FJ  
} \&b1%Asyz  
?V' zG&n@  
` *q>E  
//打印回应的头信息 @k3xk1*  
public void logResponseHead(HttpURLConnection con) uO5y{O2W  
{ `]j:''K  
for(int i=1;;i++) `XrF ,  
{ 2JL\1=k;  
String header=con.getHeaderFieldKey(i); n 'E:uXv"  
if(header!=null) fzjAP7 y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m*~Iu<5L  
Utility.log(header+" : "+con.getHeaderField(header)); Eh&-b6:  
else v`Yj)  
break; SYwB #|  
} R?iC"s!  
} #H.DnW  
"-R19SpJKh  
Mq52B_  
public void splitterStop() N;R I A  
{ 1h#e-Oyff  
bStop = true; odh cU5  
} ,*CPG$L  
<g1=jG:7k  
'f-8P  
} GS+Z(,J>=  
8 DPn5E#M1  
%gEgp Jd  
/* GUC.t7!  
**FileAccess.java |syvtS{  
*//文件访问(定位,写) Cq[<CPAS  
package NetFox; Zmz $ hr  
import java.io.*; _&e$?hY  
 6h?)x  
98XlcI#  
public class FileAccessI implements Serializable{ 7mA:~-.u  
odKdpa Zc[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T\w{&3ONm  
RandomAccessFile oSavedFile; /a }` y  
long nPos; <+_WMSf;4  
;k (M4?  
}///k]_Sh  
public FileAccessI() throws IOException t&Jrchk  
{ th%T(D5n  
this("",0); a/xnf<(H  
} z[WdJN{  
zg$NrI&  
 =@! s[  
public FileAccessI(String sName,long nPos) throws IOException 65l9dM2  
{ MG vp6/Pd  
oSavedFile = new RandomAccessFile(sName,"rw"); a+<{!+3v  
this.nPos = nPos; oAgU rl;R  
oSavedFile.seek(nPos); LwcAF g|  
} BHt9$$Z|  
}aL&3[>>  
) u1=, D  
public synchronized int write(byte[] b,int nStart,int nLen) B^Hh rz!  
{ (} wMU]!_  
int n = -1; 7{p6&xXx  
try{ \G2PK&)F  
oSavedFile.write(b,nStart,nLen); APyH.]mQ  
n = nLen; 2}rYH;Mx  
} }pKKNZ`[  
catch(IOException e) dg#w!etB  
{ eC`G0.op  
e.printStackTrace (); :"gu=u!  
} Pr3>}4M  
NUh+ &M  
P52qtN<  
return n; 0~BZh%s< (  
} T@d4NF#  
vf-8DB  
}(!3)k7*  
} ?@QcKQ@  
uOPLJ?%  
''}2JJU{  
/* kV4,45r  
**SiteInfoBean.java [y"Yi PK  
*/ 0(Hzh?t_  
package NetFox; g/gaPc*86  
*fI\|%K  
$V;0z~&!'  
public class SiteInfoBean { 5ljEh -  
Esf\Bo"  
aX? tnDv  
private String sSiteURL; //Site's URL W!JEl|]  
private String sFilePath; //Saved File's Path /|@~:5R5H  
private String sFileName; //Saved File's Name ;&XC*R+  
private int nSplitter; //Count of Splited Downloading File VyWzb  
's$/-AV  
 NG?g(  
public SiteInfoBean() m}'!W`<  
{//nSplitter的缺省值为5 *mn"G K6  
//default value of nSplitter is 5 @4$la'XSx  
this("","","",5); 0P;\ :-&p  
} TPmb]j  
,%U\@*6=  
=oTj3+7  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) " :V@AT  
{ X?Or.  
sSiteURL= sURL; Jt3*(+J>/  
sFilePath = sPath; B^C 5?  
sFileName = sName; K+`deH_d  
this.nSplitter = nSpiltter; XV1XzG#C  
J:G{  
BOv^L?)*Z  
} p tlag&Z  
pW_mS|  
G)&!f)6  
public String getSSiteURL() 0@RVM|  
{ 3e1%G#fu  
return sSiteURL; 9[h8Dy  
} UTqKL*p523  
n>xuef   
`t+;[G>ZE  
public void setSSiteURL(String value) fJ+4H4K  
{ =.qPjp_Qd  
sSiteURL = value; 0@&/W-VXg  
} q s iV  
<DhuY/o  
j9.%(*  
public String getSFilePath() l@`n4U.Gwl  
{ ps*iE=D  
return sFilePath; 2Hk21y\  
} rdH^"(  
|}@teN^J*U  
$g\p)- aU  
public void setSFilePath(String value) JY%l1:}G3  
{ f6m h_l  
sFilePath = value; s\(@f4p  
} fONycXM]  
&:~9'-O  
CKX3t:HP0  
public String getSFileName() yF-`f _  
{ %&wi@ *#  
return sFileName; Rb0{W]opt+  
} $|VdGRZ1  
xPJ @!ks9  
rr2^sQ;_  
public void setSFileName(String value) uEkGo5  
{ ;8cTy8  
sFileName = value; DIgur}q)@  
} Th4}$)yrkN  
h]}DMVV]  
A2.4#Qb'  
public int getNSplitter() w8F`RRHEE  
{ kJ)Z{hy  
return nSplitter; @ ZN@EOM$+  
} r+tHVh  
fIn^a 3TV  
M2nUY`%#v  
public void setNSplitter(int nCount) <slrzc_>&  
{ c`oW-K{  
nSplitter = nCount; N w/it*f  
} u.}H)wt  
} 8&CQx*  
\T?6TDZ]  
:g{ybTSEe  
/* !P gwFJ  
**Utility.java 9[[$5t`8  
*/ H% FP!03  
package NetFox; FLIU}doc  
FJFO0Hb6  
|{MXDx  
public class Utility { 2rHQ7  
H!|g?"C  
Xm<|m#  
public Utility() Lzx2An@R  
{ B/Ltb^a  
HrUE?Sq  
CD4@0Z+  
} *hh9 K  
,x?Jrcx~'C  
//线程睡眠 #VsS C1  
public static void sleep(int nSecond) z6|kEc"{  
{ d+"F(R9  
try{ AqH GBH0  
Thread.sleep(nSecond); qRq4PQ@  
} -J0I2D  
catch(Exception e) dJ>tM'G  
{ "#pN  
e.printStackTrace (); ?P}) Qa  
} nN>Uh T  
} `W7;-  
dvglh?7d  
//日志 p*JP='p  
public static void log(String sMsg) zLPCWP.u  
{ I/gfsyfA  
System.err.println(sMsg); $?9u;+jIR  
} Ifq|MZ\  
j`_Z`eG  
5G z~,_  
public static void log(int sMsg) )-1$y+s>  
{ |=W>4>  
System.err.println(sMsg); 9QkssI  
} yKmHTjX=  
} 5oOs.(m|*C  
la_  
lxBcO/  
/* @;[.#hK  
**TestMethod.java }( WUZ^L  
*/ N8!e(Y K_  
package NetFox; UaHN*@  
]agdVr^  
"T}HH  
public class TestMethod { >_X(rar0  
(unJwh{7Q  
$:?=A5ttuo  
public TestMethod() o/!a7>xO4  
{ ///xx/weblogic60b2_win.exe `2'*E\   
try{ 2 xi@5;!  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L)Da1<O  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w h^I|D?"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); d"+ _`d=`  
fileFetch.start(); @!(V0-  
} lPz5.(5'  
catch(Exception e){e.printStackTrace ();} g$8a B{)  
be.Kx< I  
,qhv(  
} X<H+Z2d  
u#Uc6? E  
-AKbXkc~\  
public static void main(String[] args) 1$"wN z  
{ `y.i(~^1  
new TestMethod(); TJs@V>,  
} tNW0 C]  
} ;fv/s]X86I  
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