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http断点续传简单实现(java)

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/* BN7]u5\7  
**SiteFileFetch.java eYtP396C|  
*/ t?Ku6Z'  
package NetFox; Dxvizd>VU  
import java.io.*; 1FA:"0lO  
import java.net.*; KpX1GrIn3  
s#cb wDT  
==#mlpi`S[  
public class SiteFileFetch extends Thread { ibP IT!5c  
@tT2o@2Y^  
>:J7u*>$'  
SiteInfoBean siteInfoBean = null; //文件信息Bean x&p.-Fi  
long[] nStartPos; //开始位置 ]C'^&:&<  
long[] nEndPos; //结束位置 LO;7NK  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 m+|yk.md  
long nFileLength; //文件长度 k%D|17I  
boolean bFirst = true; //是否第一次取文件 gUr #3#  
boolean bStop = false; //停止标志 H~$*R7~  
File tmpFile; //文件下载的临时信息 ,tTq25~H\  
DataOutputStream output; //输出到文件的输出流 g{6FpuA|0  
5 6JxHQu  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 8&Md=ZvK`  
public SiteFileFetch(SiteInfoBean bean) throws IOException  LA]UIM@  
{ i2P:I A|@  
siteInfoBean = bean; TI/5'Oke$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~Z`Cu~7  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); '[Zgwz;z  
if(tmpFile.exists ()) I3qTSX-  
{ x$hT+z6DUC  
bFirst = false; 'vwu^u?  
read_nPos(); Y6 <.]H  
} j DkBe-`  
else 6%^A6U  
{ P(%^J6[>  
nStartPos = new long[bean.getNSplitter()]; fK|P144   
nEndPos = new long[bean.getNSplitter()]; 2WK c;?  
} +R8G*2  
oNhCa>)/  
^>/~MCyM.  
XjXz#0nR  
} `O0bba=:=  
SPT?Tt  
W" Tj.oCUG  
public void run() #=V\WQb  
{ :u]QEZ@@  
//获得文件长度 gb{8SG5ac  
//分割文件 :\Q#W4~p  
//实例FileSplitterFetch e_YTh^wU  
//启动FileSplitterFetch线程 &#zx/$  
//等待子线程返回 dOT7;@   
try{ 7#&e0fw/I  
if(bFirst) 8S` j6  
{ ;w7s>(ITZ  
nFileLength = getFileSize(); h_HPmh5  
if(nFileLength == -1) {TXfi'\  
{ yUjkRT&h  
System.err.println("File Length is not known!"); (u4'*[o\t  
} -}1TT@  
else if(nFileLength == -2) MWv(/_b  
{ dY{qdQQ}  
System.err.println("File is not access!"); []jbzVwS2  
} F'-,Ksn  
else qizQt]l  
{ Mt4*`CxtH;  
for(int i=0;i<nStartPos.length;i++) k:F{U^!p|  
{ s<+;5, Q|  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =O/v]B8"  
} *C);IdhK%y  
for(int i=0;i<nEndPos.length-1;i++) Tb:6IC7="  
{ ~ o=kW2Y  
nEndPos = nStartPos[i+1]; U7''; w  
} Zi?:< H}  
nEndPos[nEndPos.length-1] = nFileLength; -^Qm_lN  
} &+0?Xip{Z  
} 8<x& Xd  
j&u/T  
6p9 { z42  
//启动子线程 hSz_e  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '#C5m#v  
for(int i=0;i<nStartPos.length;i++) _T_6Yl&cf)  
{ `mH]QjAO  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AJ3%Z$JJ;s  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6zi 5#23  
nStartPos,nEndPos,i); (tyky&$!  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GExr] 2r  
fileSplitterFetch.start(); p, T4BO  
} 34QW^{dgE  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I7W`\d)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^T#jBqe  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W&k@p9  
nEndPos = " + nFileLength); S17;;w0  
// fileSplitterFetch[nPos.length-1].start(); S,EL=3},=  
*07?U")  
:p%#U$S4  
//等待子线程结束 +z[+kir  
//int count = 0; "@^Q" RF  
//是否结束while循环 UhJ{MUH`  
boolean breakWhile = false; SOZs!9oi  
yDJy'Z_F{  
Gr>CdB>~+  
while(!bStop) S['cX ~  
{ ol K+|nR  
write_nPos(); I$R1#s  
Utility.sleep(500); hQ}_(F_H  
breakWhile = true; z%1e>`\E  
^f57qc3nF  
[mQdc?n\  
for(int i=0;i<nStartPos.length;i++) Y/5(BK)  
{ MsZx 0]  
if(!fileSplitterFetch.bDownOver) $o0.oY#  
{ G3 |x%/Fbp  
breakWhile = false; ,!,tU7-H  
break; `kE7PXqa  
} w+r).PS}C  
} D2GF4%|  
if(breakWhile) }'?qUy3x  
break; 8A5/jqnqt  
x4/{XRQ  
6{{<+ o  
//count++; {kBsiSvsA;  
//if(count>4) 5dhy80|g]  
// siteStop(); oaZdvu@y  
} C_'EO<w$  
E[7E%^:Mg  
 q(X7e  
System.err.println("文件下载结束!"); WNZYs  
} V= -  
catch(Exception e){e.printStackTrace ();} *o38f>aJl  
} R(*t 1R\  
RO|8NC<oj  
-Lq2K3JHyn  
//获得文件长度 V1,/qd_  
public long getFileSize() g*(z .  
{ LuHRB}W  
int nFileLength = -1; ;aj;(Z.p)  
try{ Alo L+eN@  
URL url = new URL(siteInfoBean.getSSiteURL()); ^_i)XdPU  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b;{"@b,Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); Zk/ejhy0  
`N&*+!O%  
^{{a v?h  
int responseCode=httpConnection.getResponseCode(); q)f_!N  
if(responseCode>=400) Bz <I7h  
{ )0/*j]Kf  
processErrorCode(responseCode); mE5{)<N:C  
return -2; //-2 represent access is error iE}] E  
} / Y od  
6VC|] |*  
3y+~l H :  
String sHeader; M PDRMGR@i  
h _{f_GQ"  
]8fn1Hx\  
for(int i=1;;i++) ?wv^X`Q*~  
{ ^EKRbPA9:<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qH5nw}]  
//Utility.log(in.readLine()); Jfk#E^1  
sHeader=httpConnection.getHeaderFieldKey(i); NJ+$3n om  
if(sHeader!=null) vy}_aD{B  
{ h`n '{s  
if(sHeader.equals("Content-Length")) jpO0dtn3=  
{ KS<@;Tt  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :V5 Co!/+  
break; BWQ`8  
} SMIDW}U2S  
} <F(S_w62  
else [qW%H,_  
break; |!9xL*A  
} bS2g4]$'po  
} {lH'T1^m  
catch(IOException e){e.printStackTrace ();}  ?O+.  
catch(Exception e){e.printStackTrace ();} &6C]| 13;  
tq~4W% p/  
l^}u S|c(  
Utility.log(nFileLength); xs\<!  
s+v9H10R  
/&Cq-W  
return nFileLength; 1U#W=Fg'  
} _B#x{ii  
jrFPd  
/FE+WA}r  
//保存下载信息(文件指针位置) #*/nUbsg  
private void write_nPos() =1dczJHV  
{ wn?oHz*  
try{ }nX0h6+1  
output = new DataOutputStream(new FileOutputStream(tmpFile)); dQ7iieT  
output.writeInt(nStartPos.length); wM4{\  f\  
for(int i=0;i<nStartPos.length;i++) Tx~w(A4:  
{ $kxP5q%9  
// output.writeLong(nPos); $u.rO7)  
output.writeLong(fileSplitterFetch.nStartPos); Z^2SG_pD  
output.writeLong(fileSplitterFetch.nEndPos); x?V^ l*  
} t6\H  
output.close(); %hN>o)  
} P7b"(G%  
catch(IOException e){e.printStackTrace ();} g%"SAeG<K  
catch(Exception e){e.printStackTrace ();} l[IL~  
} | n)4APX\Q  
F<4 :P=  
yna!L@ *@,  
//读取保存的下载信息(文件指针位置) ,hu@V\SKv  
private void read_nPos() HZ%V>88  
{ wkGr}  
try{ u&1M(~Ub=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i8k} B o  
int nCount = input.readInt(); fMFkA(Of^  
nStartPos = new long[nCount]; &"JC8  
nEndPos = new long[nCount]; ^7/v[J<<  
for(int i=0;i<nStartPos.length;i++) S+~;PmN9qL  
{ x%r$/=  
nStartPos = input.readLong(); (kB  
nEndPos = input.readLong(); ;$6L_C4B  
} .pWRV<25  
input.close(); b#p0s?*  
} uP%VL}% 0  
catch(IOException e){e.printStackTrace ();} ed/B.SY  
catch(Exception e){e.printStackTrace ();} hBX.GFnw  
} gEsD7]o(=  
?_d>-NC  
%;h1n6=v2  
private void processErrorCode(int nErrorCode) s=-?kcoJ2d  
{ 6]%=q)oL[  
System.err.println("Error Code : " + nErrorCode); P8ej9ULX,  
} @}H'2V  
MYvz%7  
t2{(ETV  
//停止文件下载 -e(<Jd_=  
public void siteStop() -s2)!Iko&  
{ *Vq'%b9  
bStop = true; Qc-W2%  
for(int i=0;i<nStartPos.length;i++) l<uI-RX "  
fileSplitterFetch.splitterStop(); Uz,P^\8^$  
Jj [3rt?8  
Mn/  
} gizY4~ j  
} 1}|y^oB\-  
//负责部分文件的抓取 FT~c|ep.  
**FileSplitterFetch.java M !"Q7>d  
*/ mfI[9G  
package NetFox; Bf00&PE;  
 2=;ZJ  
u`Nrg<  
import java.io.*; ";(m,i f-  
import java.net.*; qXq#A&  
nbP}a?XC  
:KvZP:T  
public class FileSplitterFetch extends Thread { _ymSo`Iv R  
cJq {;~   
6x(b/`VW  
String sURL; //File URL @q<h.#9  
long nStartPos; //File Snippet Start Position !gLJBp  
long nEndPos; //File Snippet End Position }0E@eL  
int nThreadID; //Thread's ID \R@}X cqZ  
boolean bDownOver = false; //Downing is over <ZZfN@6  
boolean bStop = false; //Stop identical P;25 F  
FileAccessI fileAccessI = null; //File Access interface hl**G4z9q  
GYIQ[#'d7  
A@lM =   
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |>j^$^l~  
{ HI D6h!  
this.sURL = sURL; ~!TrC <ft  
this.nStartPos = nStart; =r]_$r%gR  
this.nEndPos = nEnd; ^8oN~HLZ  
nThreadID = id; AX@bM  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mXJG &EA  
} 79)iv+nf\l  
%`G}/"  
mL}Wan  
public void run() Iu~(SKr=|$  
{ \J(~ Nv5!  
while(nStartPos < nEndPos && !bStop)  nSo.,72  
{ `ZC -lAY  
{yf, :5  
<]S M$) =D  
try{ nrpbQ(zI*  
URL url = new URL(sURL); T[},6I|!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A;C4>U Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); O[1Q#  
String sProperty = "bytes="+nStartPos+"-"; , 82?kky  
httpConnection.setRequestProperty("RANGE",sProperty); 2-g 5Gb2|  
Utility.log(sProperty); d<\X)-"  
+BI%. A`2  
:Oj!J&A  
InputStream input = httpConnection.getInputStream(); 6S%KUFB+e  
//logResponseHead(httpConnection);  :5^5l  
'g)5vI~'  
Tff eCaBv  
byte[] b = new byte[1024]; }/NL"0j+4  
int nRead; :8)3t! A  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u?g;fh6  
{ +)( "!@  
nStartPos += fileAccessI.write(b,0,nRead); K nn<q=';G  
//if(nThreadID == 1) UG}"OBg/  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =x^IBLHN  
} 1?p:66WmR  
ABtv|0K  
) { "}bMf  
Utility.log("Thread " + nThreadID + " is over!"); +Sv2'& B  
bDownOver = true; Sf`?j  
//nPos = fileAccessI.write (b,0,nRead); 2rP!]  
} zBrqh9%8e  
catch(Exception e){e.printStackTrace ();} i"!j:YEo  
} LGRhCOP:  
} G @L `[Wu  
r`0oI66B/  
![%:X)?  
//打印回应的头信息 G8W^XD  
public void logResponseHead(HttpURLConnection con) :Ot5W  
{ a! x?Apww  
for(int i=1;;i++) 4NFvX4  
{ ]ao%9:P;  
String header=con.getHeaderFieldKey(i); n)]u|qq  
if(header!=null) ug`Jn&x!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x2]chN  
Utility.log(header+" : "+con.getHeaderField(header)); jA%R8hdr_  
else .YS48 c  
break; Bb5RZ#oa  
} ^j_t{h)W(0  
} PTA_erU  
vN)l3  
Kzfy0LWM  
public void splitterStop()  #|l#  
{ g31\7\)Ir  
bStop = true; 6O'B:5~[2  
} eNt1P`2[  
LCpS}L;  
? i|LO  
} 5m6I:s`pK  
s)~H_,  
R? ,XSJ  
/* ;&RHc#1F  
**FileAccess.java /(A rA=#  
*//文件访问(定位,写) _H2%6t/V  
package NetFox; 9[\$\l  
import java.io.*; 'F8:|g  
2I~a{:O  
5fhe{d"si  
public class FileAccessI implements Serializable{ ?)c9!hR  
/kd6Yq(y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ud,_^Ul  
RandomAccessFile oSavedFile; 0R?LWm j  
long nPos; ->YF</I  
a: OuDjFp  
h IUO=f  
public FileAccessI() throws IOException [E%Ov0OC  
{ I9r> 3?  
this("",0); p8u -3  
} c f1GA  
jP"='6Vrw  
)VR/a  
public FileAccessI(String sName,long nPos) throws IOException W\yaovAt  
{ =_dqoAF  
oSavedFile = new RandomAccessFile(sName,"rw"); %MUwd@,  
this.nPos = nPos; <~!R|5sK  
oSavedFile.seek(nPos); +D+Rf,D  
} w=75?3c7F  
2SVJKX_V+  
/3v`2=b  
public synchronized int write(byte[] b,int nStart,int nLen) L[:b\ O/p,  
{ 3/((7O[  
int n = -1; < G:G/  
try{ ob.=QQQs  
oSavedFile.write(b,nStart,nLen); w!^{Q'/,Q  
n = nLen; PP)-g0^@  
} W[tX%B  
catch(IOException e) ::rKW *?  
{ -}*YfwK  
e.printStackTrace (); MXU8QVSY"  
} 41`&/9:"_M  
4m$Xjj`vE  
"*aL(R  
return n; dD8f`*"*=  
} ~~'UQnUN4  
zc#aQ.  
5S ?+03h~  
} [S!_ubP5  
)o8]MWT\;  
pO_L,~<  
/* ({AqL#x`u  
**SiteInfoBean.java | sio:QP  
*/ =XT}&D6  
package NetFox; ~<#!yRy>r  
U#!f^@&AB  
!G3d5d2)C  
public class SiteInfoBean { 07L 1 "  
/"<o""<]  
zcNv T  
private String sSiteURL; //Site's URL 42: 6=\  
private String sFilePath; //Saved File's Path ;4 ON  
private String sFileName; //Saved File's Name gNG_,+=!  
private int nSplitter; //Count of Splited Downloading File ]RJcY1  
m0 k~8^L@f  
fgSe]q//  
public SiteInfoBean() _7"G&nZ0  
{//nSplitter的缺省值为5 Pb^Mc <j  
//default value of nSplitter is 5 ("L&iu\`@  
this("","","",5); Bzw!,(u/ "  
} 4U;6 2 jq  
k/ 9S  
^B|Q&1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B@W`AD1^{  
{ @ukIt  
sSiteURL= sURL; !h0#es\  
sFilePath = sPath; tb-:9*2j-  
sFileName = sName; AG$S;)Yl9c  
this.nSplitter = nSpiltter; A<VNttgG  
amn\#_(  
*g<D p2`  
} n_/_Y >{M0  
 hVB^:  
P+~{q.|._c  
public String getSSiteURL() C"P40VQoo  
{ VY5/C;0^h  
return sSiteURL; Je#vl4<L  
} X^U)j N2  
j[fVF3v  
TYQ7jt0=.-  
public void setSSiteURL(String value) 9_z u*  
{ ,5_Hen=PI  
sSiteURL = value; ./009p  
}  Wb/q&o  
zMkjdjb  
sacaL4[_<  
public String getSFilePath() jz%%r Q(  
{ i0%S6vmaS  
return sFilePath; 7aJLC!  
} ^$7Lmd.qI  
N{u4  
lIg;>|'Z5&  
public void setSFilePath(String value) j~eYq  
{ 6mnj!p]3  
sFilePath = value; xi.L?"^/!  
} y-TS?5Dr]  
L`$MOdF{_  
rVx%"_'*-  
public String getSFileName() #mNM5(o  
{ i%8I (F  
return sFileName; w>:~Ev]  
} ]e'Ol$3U9=  
MHv2r  
S'NZb!1+  
public void setSFileName(String value) X/_e#H0  
{ w~eF0 {h  
sFileName = value; a+TlZE>8  
} pFLR!/J  
9~^%v zM  
 Sxrbhnx  
public int getNSplitter() 4,!S?:7  
{ )pS1yYLj  
return nSplitter; 4|ryt4B  
} =#AeOqs( q  
cvR|qHNX  
!}D!_z,)u  
public void setNSplitter(int nCount) +)#d+@-  
{ P~V0<$C  
nSplitter = nCount; q^ {Xn-G  
} >g ]S"ku|  
} aN7VGc  
/hPgOaB  
V=pg9KR!T  
/* T>l=0a #  
**Utility.java W 2VH?-Gw  
*/ -vcHSwG b  
package NetFox; (%huWW j  
<n iq*  
5G@z l  
public class Utility { ^FJ=/#@T  
;&Q8xC2  
}xx[=t=nUf  
public Utility() IS`1}i$1%  
{ Ixhe86-:T  
@;iW)a_M  
6% @@~"  
} ;?>xuC$  
+1j@n.)ft  
//线程睡眠 #2thg{5  
public static void sleep(int nSecond) Vx5ioA]{  
{ Iz/o|o]#  
try{ 8}3dwr;-  
Thread.sleep(nSecond); c7mIwMhl~  
} X'4g\)*  
catch(Exception e) / c1=`OJ  
{ aVI/x5p~  
e.printStackTrace (); zPp?D_t  
} YN1P9j#0d  
} d`D<PT(\  
)GDP?Nc<Ik  
//日志 lE~5 b  
public static void log(String sMsg) }(h_ztw  
{ >t|u 8/P  
System.err.println(sMsg); =.9L/74@  
} Xqt3 p6  
uXiAN#1  
 <StyO[  
public static void log(int sMsg) G992{B  
{ Y27x;U  
System.err.println(sMsg); {AbQaw  
} @EZ@X/8{&  
} 5Z]zul@+*  
:-B,Q3d  
zY\pZG  
/* 1ID0'j$  
**TestMethod.java 7mipj]  
*/ X\tE#c&K  
package NetFox; H]V@Q~?e  
{VBx;A3*I  
29DYL  
public class TestMethod { xc.(-g[  
jm1f,=R  
5mwtlC':l?  
public TestMethod() :kUZNw'Bi  
{ ///xx/weblogic60b2_win.exe F-?K]t#  
try{ iUl5yq  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .4c*  _$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YPQ&hEu0  
SiteFileFetch fileFetch = new SiteFileFetch(bean); tMxa:h;/x  
fileFetch.start(); vT)(#0>z  
} R=g~od[N_  
catch(Exception e){e.printStackTrace ();} 7iCH$}  
gs)wQgJ[  
!|hxr#q=4  
} >p4#AfGF  
M>+FIb(  
4LqJ4jo  
public static void main(String[] args) }J27Y ;Zp9  
{ { -*+G]  
new TestMethod(); (Zi(6 T\z  
} kwRXNE(k]_  
} tz&'!n}  
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