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http断点续传简单实现(java)

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/* N'.+ezZ;h  
**SiteFileFetch.java Vtk|WV?>P+  
*/ bUL9*{>G  
package NetFox; '" yl>"  
import java.io.*; be@uHikp;v  
import java.net.*; 3o^M%  
<-aI%'?*  
>1zzDd_  
public class SiteFileFetch extends Thread {  p$v +L  
z*1K<w8  
EOC"a}Cq-  
SiteInfoBean siteInfoBean = null; //文件信息Bean fdW={}~  
long[] nStartPos; //开始位置 ?!-im*~w  
long[] nEndPos; //结束位置 #C}(7{Vt  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 7?#32B Gr  
long nFileLength; //文件长度 54%}JA][  
boolean bFirst = true; //是否第一次取文件 JFdzA  
boolean bStop = false; //停止标志 Okc*)crw  
File tmpFile; //文件下载的临时信息 8 \Oiv$r  
DataOutputStream output; //输出到文件的输出流 ?Qk#;~\yB  
)CQ}LbXZy  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) !%9I%Ak^  
public SiteFileFetch(SiteInfoBean bean) throws IOException DJUtuex  
{ X|G+N(`|(  
siteInfoBean = bean; Ry3 f'gx  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 3/05ee;|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Bk <P~-I  
if(tmpFile.exists ()) 4VgDN(n0@  
{ P^-9?u Bno  
bFirst = false; ?yK\L-ad  
read_nPos(); ]aL}&GlHt  
} gvYs<,:  
else B[50{;X  
{ 2_v>8B  
nStartPos = new long[bean.getNSplitter()]; :"]ei@  
nEndPos = new long[bean.getNSplitter()]; LcF3P 4  
} :LG%8Z{R  
!CKUkoX  
h65j,v6B  
rg.if"o  
} pXa? Q@ 6  
N3) v,S-  
k*^W lCZ3  
public void run() # w6CL  
{ l[k$O$jo  
//获得文件长度 :B~c>:  
//分割文件 YZ@-0_Z  
//实例FileSplitterFetch \f#ao<vQm  
//启动FileSplitterFetch线程 [%kucGC7  
//等待子线程返回 _TF>c:m3  
try{ Zlo,#q  
if(bFirst) gZv <_0N  
{ Hc9pWr "N  
nFileLength = getFileSize(); SGm? "esEt  
if(nFileLength == -1) 9_{!nQC.g  
{ (=9&"UH  
System.err.println("File Length is not known!"); c2/HY8ttRD  
} XT"c7]X  
else if(nFileLength == -2) Gy%e%'  
{ 1O4"MeF  
System.err.println("File is not access!"); bk]|C!7$  
} ,vPF=wq  
else H;1}Nvvd  
{ ;\N*iN#K  
for(int i=0;i<nStartPos.length;i++) M5uN1*   
{ P_U-R%f  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); d9"4m>ymS  
} $}fA;BP  
for(int i=0;i<nEndPos.length-1;i++) ev $eM  
{ 5>Q)8` @E  
nEndPos = nStartPos[i+1]; ZD(gYNi  
} U,BB C  
nEndPos[nEndPos.length-1] = nFileLength; 8vK&d>  
} J^4k}  
} 2wCRT}C  
FQ%mNowuj  
5FxU=M1gF  
//启动子线程 !=:c8V  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  ~A/_\-  
for(int i=0;i<nStartPos.length;i++) x#D=?/~/Kv  
{ 3 6 ;hg #  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {W]jVh p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AK HH{_  
nStartPos,nEndPos,i); {QID@  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nKdLhCN'=  
fileSplitterFetch.start(); Q1z04m1_y[  
} b3+PC$z2h  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Ny&;Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +Sfv.6~v  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o6 /?WR9  
nEndPos = " + nFileLength); Cmj)CJ-  
// fileSplitterFetch[nPos.length-1].start(); q@:&^CS  
"|if<hx+  
3nO|A: t  
//等待子线程结束 $$a"A(Y  
//int count = 0; tF|bxXs Z  
//是否结束while循环 (&(f`c@I  
boolean breakWhile = false; <T).+ M/  
Cp%|Q.?  
Ee O{G*pq  
while(!bStop) 0*)79Sz  
{ U{EW +>  
write_nPos(); q<VhP2R  
Utility.sleep(500); (P?9Jct  
breakWhile = true; `;;!>rm  
- g0>>{M'  
i(WWF#N 5  
for(int i=0;i<nStartPos.length;i++) #=rR[:M  
{ 7F.,Xvw&@  
if(!fileSplitterFetch.bDownOver) s6B@:9  
{ ]G:xTv8  
breakWhile = false; kbY@Y,:w  
break; [C$ 0HW  
} 5 S 1m&s5k  
}  <CFu r  
if(breakWhile) W4<}w-AoEp  
break; *q RQN+%  
)-(NL!?`  
o0 Ae*Y0  
//count++; G;e}z&6<k  
//if(count>4) 5j]%@]M$Z  
// siteStop(); (k?OYz]c  
} -LyIu#  
om1 / 9  
L$g;^@j  
System.err.println("文件下载结束!"); pfT7  
} (I$hw"%&  
catch(Exception e){e.printStackTrace ();} :O7J9K|  
} 6XP>p$-  
tVOx  
$[Fk>d  
//获得文件长度 5M*p1^ >  
public long getFileSize() =F9-,"EAI  
{ x-1[2K1"[  
int nFileLength = -1; ^N]*Zf~N?  
try{ oW6.c]Vo  
URL url = new URL(siteInfoBean.getSSiteURL()); WCH>9Z>cj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >9 iv>  
httpConnection.setRequestProperty("User-Agent","NetFox"); KvQ9R!V  
du !.j  
"jSn`  
int responseCode=httpConnection.getResponseCode(); FB@G.f  
if(responseCode>=400) yZ`\.GgC^&  
{ (~jOtUyT  
processErrorCode(responseCode); WI%,m~  
return -2; //-2 represent access is error _/Hu'9432  
} -a3C3!!  
N$ ?qAek  
YW*ti|u|w  
String sHeader; C RNO4  
vQ;Z 0_  
%]-tA,u  
for(int i=1;;i++) t?\osPL  
{ {S?.bT%&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W+QI D/  
//Utility.log(in.readLine()); DD1S]m  
sHeader=httpConnection.getHeaderFieldKey(i); x-[l`k.V  
if(sHeader!=null) N67m=wRx  
{ FX{Sb"  
if(sHeader.equals("Content-Length")) /O9z-!Jz  
{ aa|xZ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C-8@elZ1  
break; `!i>fo~  
} <*L8kNykK  
} E:2Or~  
else NunT1ved  
break; Af;$}P  
} ="V6z$N  
} x`4">:IA  
catch(IOException e){e.printStackTrace ();} e. [h  
catch(Exception e){e.printStackTrace ();} "h "vp&A  
C`fQ` RL\  
|q?A8@\u  
Utility.log(nFileLength); =vR>KE  
IMj{n.y4  
;*8$BuD  
return nFileLength; i]P]o)  
} Na4\)({  
0VPa=AW  
d2pVO]l YZ  
//保存下载信息(文件指针位置) ]c08`  
private void write_nPos() v''$qMQ)  
{ MZ0 J/@(  
try{ ,ecFHkT>  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]\{EUx9  
output.writeInt(nStartPos.length); _o;alt  
for(int i=0;i<nStartPos.length;i++) L~\Ir  
{ j sm{|'  
// output.writeLong(nPos); =oBV.BST u  
output.writeLong(fileSplitterFetch.nStartPos); E;yP.<PW  
output.writeLong(fileSplitterFetch.nEndPos); ig6F!p  
} q:fkF^>  
output.close(); 8q_nOGd  
} `On%1%k8  
catch(IOException e){e.printStackTrace ();} :V&#Oo  
catch(Exception e){e.printStackTrace ();} -LUKYGBK  
} /)j:Y:5  
{a(TT)d  
$. Ih-  
//读取保存的下载信息(文件指针位置) 7"1M3P5*8  
private void read_nPos() ^5OR%N)  
{ )Zox;}WK+  
try{ KrB"2e+J  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wtK+\Qnb  
int nCount = input.readInt(); ->d 3FR  
nStartPos = new long[nCount]; svN& ~@ l  
nEndPos = new long[nCount]; y6f YNB  
for(int i=0;i<nStartPos.length;i++) @PutUYz  
{ <d8 Yk>R  
nStartPos = input.readLong(); 'bTtdFvJ  
nEndPos = input.readLong(); `2G 0B@  
} ^)TZHc2a[  
input.close(); D KR2b`J  
} Y f1?3 (0O  
catch(IOException e){e.printStackTrace ();} >o.4sN@  
catch(Exception e){e.printStackTrace ();} T< D&%)  
} ta %yQd7  
u{J$]%C   
F8nR.|  
private void processErrorCode(int nErrorCode) *y0TtEd;  
{ 05Ak[OOU>  
System.err.println("Error Code : " + nErrorCode); S3$&}I <  
} BKi@c\Wb  
eot%T h?[  
`@RTfBB g  
//停止文件下载  _->d41  
public void siteStop() EJrP{GH  
{ iU+O(vi  
bStop = true; xQ%N% `  
for(int i=0;i<nStartPos.length;i++) =A{F&:+a]  
fileSplitterFetch.splitterStop(); ) vn {?Ulj  
;ry~x:7L7  
Pd)mLs Jg  
} XkDIP4v%  
} I|(r1.[K  
//负责部分文件的抓取 "\3C)Nz?  
**FileSplitterFetch.java ~m3Q^ue  
*/ yhc}*BMZ  
package NetFox; a[I :^S  
mb,\wZ  
vhvFBx0  
import java.io.*; %py3fzg  
import java.net.*; T,r?% G{XE  
shKTj5s?  
$Y,y~4I  
public class FileSplitterFetch extends Thread { h/k00hD60  
xPCRT*Pd  
T\q:  
String sURL; //File URL 9eBD)tnw  
long nStartPos; //File Snippet Start Position >P@g].Q-  
long nEndPos; //File Snippet End Position a5cary Z"z  
int nThreadID; //Thread's ID #x*\dL  
boolean bDownOver = false; //Downing is over ~bf4_5  
boolean bStop = false; //Stop identical H%pD9'q~  
FileAccessI fileAccessI = null; //File Access interface 2{|Z?3FJ^  
SMo nJ;Y  
i]9C"Kw$L  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {^8?fJ/L  
{ w{mw?0  
this.sURL = sURL; xu\s2x$  
this.nStartPos = nStart; @CMEmgk~  
this.nEndPos = nEnd; `3g5n:"g\  
nThreadID = id; FRa>cf4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B`|f"+.  
} ZmI0|r}QbY  
f*}}Az.4  
DQ<4`wEM  
public void run() nr&bpA/  
{ ijP `fM8  
while(nStartPos < nEndPos && !bStop) .exBU1Yk@  
{ ?zex]!R  
>$,P )cB'  
>v2/0>U  
try{ D%L^[|)c\s  
URL url = new URL(sURL); __!LTpp  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D6-R>"}  
httpConnection.setRequestProperty("User-Agent","NetFox"); P?p]sLrP  
String sProperty = "bytes="+nStartPos+"-"; |M`'   
httpConnection.setRequestProperty("RANGE",sProperty); I3HO><o f  
Utility.log(sProperty); )pSA|Qt N  
t W+"/<U  
$GP66Ev  
InputStream input = httpConnection.getInputStream(); 60;_^v  
//logResponseHead(httpConnection); eSQkW  
}{y)a<`  
EHN(K-  
byte[] b = new byte[1024]; OClG dFJ|  
int nRead; NOg/rDs'{  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0<7sM#sI!  
{ k4a51[SYBK  
nStartPos += fileAccessI.write(b,0,nRead); _3(rwD  
//if(nThreadID == 1) !wN2BCSY@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \3OEC`  
} Ge_fU'F  
+5S>"KAUt0  
URceq2_  
Utility.log("Thread " + nThreadID + " is over!"); yDfH`]i)U  
bDownOver = true; ?7}ybw3t]  
//nPos = fileAccessI.write (b,0,nRead); l`.z^+!8@  
} D&i\dgbK  
catch(Exception e){e.printStackTrace ();} FQJiLb._Z  
} %N)B8A9kh  
} To}eJ$8*5  
Q 9fK)j1$  
EB| iW2'  
//打印回应的头信息 dP?prT  
public void logResponseHead(HttpURLConnection con) M!+J[q  
{ ?z`={oN  
for(int i=1;;i++) oUwo!n}  
{ 3CgID6[Sy  
String header=con.getHeaderFieldKey(i); <o/!M6^:  
if(header!=null) b{qN7X~>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); SV@*[r  
Utility.log(header+" : "+con.getHeaderField(header)); <l(n)|H1P  
else MA,*$BgZ  
break; ltf KqY-  
} <3!Al,!ej@  
} )by7 [I0v  
Tf~eH!~0  
iLch3[p%  
public void splitterStop() o3V\   
{ <Y."()}GeH  
bStop = true; o2X95NiH  
} :`e#I/,  
 V1B!5N<  
5mQ@&E~#W  
} 9 wZ?")2  
@4hzNi+  
g'KxjjYT,  
/* ffG<hclk  
**FileAccess.java PJiU2Y33  
*//文件访问(定位,写) o`QNZN7/}  
package NetFox; x(._?5  
import java.io.*; w+/`l*  
 Z/%FQ  
/i3 JP}  
public class FileAccessI implements Serializable{ OL>)SJj5  
H.\`(`6  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T[ZmD{6l  
RandomAccessFile oSavedFile; Rjq Xz6  
long nPos; ss[`*89  
`mzlOB  
M2Jf-2  
public FileAccessI() throws IOException Ux7LN @4og  
{ Ez;Qo8  
this("",0); JD#x+~pb,8  
} [EDX@Kdq)  
GuO}CQs^W  
<Cv(@A->  
public FileAccessI(String sName,long nPos) throws IOException HD^#"  
{ 6LBdTnzUd  
oSavedFile = new RandomAccessFile(sName,"rw"); ao2^3e  
this.nPos = nPos; nS04Ha  
oSavedFile.seek(nPos); .26mB Xr  
} K f/[Edn  
~.aR=m\#  
W}f)VC;D  
public synchronized int write(byte[] b,int nStart,int nLen) nd]SI;<  
{ (da`aRVDp  
int n = -1; B:T s_9*  
try{ E +_n@t"  
oSavedFile.write(b,nStart,nLen); Jqj!k*=/  
n = nLen; H:@hCO[a  
} zbmC? 2$  
catch(IOException e) Z+&V  >  
{ +P^ ;7"H  
e.printStackTrace (); @khFk.LBD  
} x "{aO6M  
SI=$s>1  
=0pt-FQ  
return n; wAKHD*M)  
} f`n4'dG  
Z^_qXerjP  
!?nbB2,  
} q#tUDxf(|  
5p (zhfuG  
_K o#36.S  
/* C`hdj/!A  
**SiteInfoBean.java eR$@Q  
*/ LH5Z@*0#  
package NetFox; }T@=I&g;  
&eHRn_st5b  
HU'Mi8xxy  
public class SiteInfoBean { M76p=*  
5EFt0?G   
2#>;cn\  
private String sSiteURL; //Site's URL ,X.[37  
private String sFilePath; //Saved File's Path z:>cQUYl  
private String sFileName; //Saved File's Name 2aj1IBnz6/  
private int nSplitter; //Count of Splited Downloading File 8:$h&aBI  
t(u2%R4<d  
=]%JTGdp(  
public SiteInfoBean() VBX)xQazU  
{//nSplitter的缺省值为5 0~bUW V  
//default value of nSplitter is 5 Wef%f] u  
this("","","",5); C|V7ZL>W  
} ; Z]Wj9iY  
ij ?7MP  
'XK 'T\m  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g&s. 0+  
{ PMfW;%I.  
sSiteURL= sURL; 4yyw:"  
sFilePath = sPath; JT?u[p Q^  
sFileName = sName; Dh8ECy5k<*  
this.nSplitter = nSpiltter; gQ_<;'m)2  
)2&3D"V  
tm+*ik=x|  
} pey=zR!  
G?s9c0f  
o;$xN3f,  
public String getSSiteURL() 'JOUx_@z  
{ ;7'O=%  
return sSiteURL; $Zu?Gd?  
} Ymz/:  
gJQ#j~'  
:W.H#@'(  
public void setSSiteURL(String value) [Fl_R[o  
{ )9hqd  
sSiteURL = value; WC#6(H5t$  
} V&*IZt&  
}u_D{bz  
`HX:U3/  
public String getSFilePath() duaF?\vv  
{ W/qXQORv  
return sFilePath; L7$f01*  
} g-eJan&]N  
5W&L6.J}+  
2][9Wp  
public void setSFilePath(String value) danPy2  
{ rtj/&>  
sFilePath = value; 39v Bsc  
} QP (0  
y98FEG#S}  
(VeK7cU  
public String getSFileName() ^&qK\m_A  
{ ,b*?7R  
return sFileName; CD&a_-'z$K  
} $94lF~  
#_DpiiS,.Q  
,Kv6!ib6Q  
public void setSFileName(String value) $|~ <6A{y  
{ uj8saNu  
sFileName = value; 287j,'vR  
} ^B<-.(F  
t\M6 d6  
eC-&.Fl  
public int getNSplitter()  NNt n  
{ 90vWqL!  
return nSplitter; w!m4>w  
} 4|?(LHBD)  
1aAOT6h  
Qc7*p]E&  
public void setNSplitter(int nCount) [+\He/M6  
{ 2j-l<!s  
nSplitter = nCount; A%^?z.  
} ctP+ECH  
} vFUp$[  
k-~}KlP  
f Fi=/}  
/* In?rQiD9  
**Utility.java ^T&{ORWz  
*/ WsHD Ip  
package NetFox; fEBi'Ad  
%r^tZ;; l  
 .\oz  
public class Utility { Ic'D# m  
G#%Sokkb'  
& DP"RWT/  
public Utility() TCp9C1Q4  
{ <Y`(J#  
A|"T8KSMB  
v?He]e'  
} jkk%zu  
zZMKgFR@  
//线程睡眠 O~5t[  
public static void sleep(int nSecond) D"4*l5l  
{ b$@I(.X:  
try{ "09v6Tx  
Thread.sleep(nSecond); |b\a)1Po:  
} Ce+:9}[  
catch(Exception e) mZiKA-t  
{ ThV>gn5  
e.printStackTrace (); y3;M$Jr  
} }1 O"?6  
} PJK:LZw  
KH2]:&6:Q  
//日志 6w%n$tiX  
public static void log(String sMsg) `oMZ9Gq2E  
{ a j4ZS  
System.err.println(sMsg); Xm,fyk>  
} g[~{iu_$d  
y(DT ^>0  
2*sTU  
public static void log(int sMsg) &<><4MQ  
{ M[qhy.  
System.err.println(sMsg); ?b7ttlX{  
} {J"]tx9 ]  
} 2D:/.9= 8v  
7)U ik}0  
3FvVM0l"  
/* Fx!D:.)/G  
**TestMethod.java ^x0N] /  
*/ 6 |=]i-8  
package NetFox; k{r<S|PK0  
;=joQWNDm  
!Ge;f/@  
public class TestMethod { T`^Jw s{;7  
e#hg,I  
O1\4WG%  
public TestMethod() 5@RcAQb:  
{ ///xx/weblogic60b2_win.exe * K$ U[$s  
try{ *-ys}sX  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T @^ S:K  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %f<>Kwr`2  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !n;3jAl&$  
fileFetch.start(); fln[Q2zl  
} w7` pbcY,  
catch(Exception e){e.printStackTrace ();} S0StC$$1  
Ab[o~X"  
b"\lF1Nf&o  
} 6Gg`ExcT5  
1Xi>&;],  
sSh." H  
public static void main(String[] args) &yP|t":HWX  
{ @(c^u;  
new TestMethod(); 8 AW}7.<5  
} v#gXXO[P1  
} I:t ?#)wl  
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