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http断点续传简单实现(java)

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/* u{H?4|'(  
**SiteFileFetch.java BRRj$)u  
*/ |UnUG  
package NetFox; | bv,2uWz  
import java.io.*; bCv{1]RC2  
import java.net.*; E2wz(,@  
n$L51#'  
@ EuFJ=h  
public class SiteFileFetch extends Thread { LJlZ^kh  
aBuoHdg;  
V&{MQWy  
SiteInfoBean siteInfoBean = null; //文件信息Bean rJyCw+N0  
long[] nStartPos; //开始位置 >h~IfZU1  
long[] nEndPos; //结束位置 je,}_:7  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 = "ts`>  
long nFileLength; //文件长度 |,C#:"z;  
boolean bFirst = true; //是否第一次取文件 }WLh8i?_  
boolean bStop = false; //停止标志 Av J4\  
File tmpFile; //文件下载的临时信息 +~zXDBS9  
DataOutputStream output; //输出到文件的输出流 "\%On >  
%r{3wH# D@  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) mB'3N;~  
public SiteFileFetch(SiteInfoBean bean) throws IOException jdA ]2]  
{ sy* y\5yJ  
siteInfoBean = bean; \K2*Q&>  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); o89( h!  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Dh| w^Q  
if(tmpFile.exists ()) qQ[b VD\*  
{ 3Hi+Z}8  
bFirst = false; I<oL}f  
read_nPos(); >`RRP}u=u  
} Ut@RGg+f8  
else yBpk$  
{ eU+ {*YJg  
nStartPos = new long[bean.getNSplitter()]; 4vnUN  
nEndPos = new long[bean.getNSplitter()]; f>jwN@(  
} +|cI:|H>  
h!@,8y[B  
JtKp(k&  
<i?a0  
} g\fhp{gWB  
;!>Wz9  
Xf'=+f2p  
public void run() a dfR!&J  
{ ,U,By~s  
//获得文件长度 C]u',9,  
//分割文件 9' 1B/{  
//实例FileSplitterFetch E\7m< 'R  
//启动FileSplitterFetch线程 )}v 3q6?_  
//等待子线程返回 3L>IX8_   
try{ '_s}o<  
if(bFirst) {Bvj"mL]j  
{ ,Z9>h[JF  
nFileLength = getFileSize(); iO w3MfO  
if(nFileLength == -1) *hhmTc#  
{ /hWd/H]  
System.err.println("File Length is not known!"); 4Aes#{R3v  
} ,Dmc2D  
else if(nFileLength == -2) ]:]H:U]p  
{ +]xFoH  
System.err.println("File is not access!"); )P&9A)8  
} y8Xv~4qQW  
else F'8T;J7  
{ >T3H qYX5W  
for(int i=0;i<nStartPos.length;i++) &Nl2s ey  
{ M6|I6M<  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5E\#%K[  
} +YY8h>hj  
for(int i=0;i<nEndPos.length-1;i++) 83~ i:+;  
{ pcS+o  
nEndPos = nStartPos[i+1]; b}9[s  
} FwAKP>6*  
nEndPos[nEndPos.length-1] = nFileLength; | $^;wP  
} U 5w:"x  
} LHCsk{3  
w?vVVA  
.Ce8L&cU  
//启动子线程 OWjJxORB  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; . v)mZp  
for(int i=0;i<nStartPos.length;i++) *V^ #ga#A  
{ &[R8Q|1 j  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8^^[XbH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MhEw _{?  
nStartPos,nEndPos,i); !eR3@%4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S0/usC[r  
fileSplitterFetch.start(); $P o}  
} V3N0Og3  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cR{>IH4^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4'pS*v  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2C^B_FUg|]  
nEndPos = " + nFileLength); LE^G&<!  
// fileSplitterFetch[nPos.length-1].start(); [s1pM1x  
P'Q$d+F,  
m*0,s  
//等待子线程结束 L6P1L)  
//int count = 0; DC+wD Bp;  
//是否结束while循环 SS|z*h Z  
boolean breakWhile = false; ;oO v/3  
v`[Eb27W.  
N^0uit  
while(!bStop) i8X`HbmN  
{ CG]Sj*SA~  
write_nPos(); :,pSWfK H  
Utility.sleep(500);  4-Z()F  
breakWhile = true; ;$j7H&UNQj  
Btt]R  
Yepe=s+9  
for(int i=0;i<nStartPos.length;i++) ?kw&=T !  
{ al9.}  
if(!fileSplitterFetch.bDownOver) \(UKd v  
{ L #[]I,  
breakWhile = false; Z{NC9  
break; VObrlOkp  
} j5$BK[p.  
} bF}V4"d,B3  
if(breakWhile) `<"m%>  
break; 9Mm!%Hu  
yR~-k?7b  
iX{G]< n  
//count++; 1t[j"CG(o  
//if(count>4) 9a$56GnW1  
// siteStop(); {NM+Oj,~'  
} )QiQn=Ce  
`em9T oJV  
SF ]@|  
System.err.println("文件下载结束!"); FE7)E.U  
} rEZ8eeB[3  
catch(Exception e){e.printStackTrace ();} 5 LP?Ij  
} m#H3:-h,  
Ei>m0 ~<\  
C_:k8?  
//获得文件长度 AF,BwLN  
public long getFileSize() HG >j5  
{ Br>Fpe$q4  
int nFileLength = -1; u~zs* qp  
try{ lb' Cl3H  
URL url = new URL(siteInfoBean.getSSiteURL()); F9q8SA#"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7\ SUr9[  
httpConnection.setRequestProperty("User-Agent","NetFox"); BZK`O/  
[|`U6 8}u  
-_VG;$,jE  
int responseCode=httpConnection.getResponseCode(); 3*S{;p  
if(responseCode>=400) ?ne_m:J[  
{ R! s6% :Yg  
processErrorCode(responseCode); oSb, :^Wl  
return -2; //-2 represent access is error >n5:1.g  
} xh@-g|+g  
eBN)g^  
g\oSG)  
String sHeader; 3#kitmV  
"v*8_El  
L}{`h  
for(int i=1;;i++) \Xrw"\")j  
{ k5d\ w@G"~  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &.i^dO^}  
//Utility.log(in.readLine()); IputF<p  
sHeader=httpConnection.getHeaderFieldKey(i); LS>G4 ]  
if(sHeader!=null) =8 G&3 R  
{ pj|pcv^  
if(sHeader.equals("Content-Length")) Q'B6^%:<~  
{ tS# `.F~y  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5 +9 Ze9  
break; :bU(S<%M  
} Ac k}QzXO  
} :HViX:]H  
else +~Cy$M CX  
break; /x@RNdKv  
} c2SC|s]  
} ^W83ByP  
catch(IOException e){e.printStackTrace ();} zRl~^~sY  
catch(Exception e){e.printStackTrace ();} DLPUqKL]  
+';>=hha  
"L"150Ih  
Utility.log(nFileLength); {43yb_B(  
Z5G!ct:W  
kQdt}o])  
return nFileLength; &7?R+ZGo  
} DsDzkwJE  
z;u> Yz+3  
0CvsvUN@  
//保存下载信息(文件指针位置) t/i5,le  
private void write_nPos() C2e.2)y  
{ %n0;[sD0A  
try{ UnWW/]E  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T0HuqJty  
output.writeInt(nStartPos.length); W\*-xf|"d  
for(int i=0;i<nStartPos.length;i++) }b3/b  
{ 1-SVCk -  
// output.writeLong(nPos); A!W0S  
output.writeLong(fileSplitterFetch.nStartPos); d?idTcgs  
output.writeLong(fileSplitterFetch.nEndPos); "GT4s?6O  
} @!=\R^#p  
output.close(); gA#RM5x@  
} { Ng oYl  
catch(IOException e){e.printStackTrace ();} )+I.|5g  
catch(Exception e){e.printStackTrace ();} @# P0M--X  
} vP!GJX &n5  
mumXUX  
]pA(K?Lbg  
//读取保存的下载信息(文件指针位置) : DG)g3#  
private void read_nPos() *2 "6fX[  
{ rk2xKm^w  
try{ }|)R   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C@y8.#l  
int nCount = input.readInt(); AS!6XT  
nStartPos = new long[nCount]; 5,"l0nrk  
nEndPos = new long[nCount]; 3{Nbp  
for(int i=0;i<nStartPos.length;i++) %rQuBi# 1f  
{ `\>.h  
nStartPos = input.readLong(); Lr;(xw\['  
nEndPos = input.readLong(); z~6y+  
} z1OFcqm  
input.close(); UQ Co}vM  
} < O*6 T%;  
catch(IOException e){e.printStackTrace ();} ;d.K_P  
catch(Exception e){e.printStackTrace ();} Q }k.JS~#  
} 8Chj w wB  
*TW=/+j  
KP;(Q+qTx  
private void processErrorCode(int nErrorCode) Uh}seB#mJj  
{ d87vl13  
System.err.println("Error Code : " + nErrorCode); V5}nOGV9  
} V2Q$g^X'  
SD\= m/W  
/{2*WI;  
//停止文件下载 }n,Zl>T9  
public void siteStop() Myat{OF  
{ qMBR *f  
bStop = true; Is<"OQ  
for(int i=0;i<nStartPos.length;i++) 1&=0Wg0ig  
fileSplitterFetch.splitterStop(); ;.s l*q1A  
.k{ j]{k  
u#7+U\  
} Q~D`cc|]  
} IHfzZHy  
//负责部分文件的抓取 `L;eba  
**FileSplitterFetch.java MjfFf} @  
*/ l*b)st_p%  
package NetFox; PQW(EeQ  
Gnm4gF!BI  
- "*r  
import java.io.*; B DY}*cX  
import java.net.*; >Y 1{rSk  
K[\'"HyQ,X  
.ujT!{>v/  
public class FileSplitterFetch extends Thread { yj6@7@l>A  
X#a`K]!B  
57{oh")  
String sURL; //File URL {)f~#37  
long nStartPos; //File Snippet Start Position UnDgu4#R`A  
long nEndPos; //File Snippet End Position DQ.v+C,  
int nThreadID; //Thread's ID /(I*,.d  
boolean bDownOver = false; //Downing is over r5&I? 0   
boolean bStop = false; //Stop identical \b'x t  
FileAccessI fileAccessI = null; //File Access interface inPJ2uBD\^  
u.pxz8  
Sx gYjIa-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I7QCYB|  
{ :A46~UA!$  
this.sURL = sURL; :^ i9]  
this.nStartPos = nStart; '+'CbWgY  
this.nEndPos = nEnd; <<9Va.  
nThreadID = id; ! ueN|8'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I[MgIr^  
} Z{IUy  
0rk]/--FGJ  
^_I} x)i*@  
public void run() M/D)".;  
{ <BWkUZz\P|  
while(nStartPos < nEndPos && !bStop) pZZgIw}aS  
{ j;yf8Nf  
&MR/6"/s  
z9 u$~  
try{ k?BJdg)xJ  
URL url = new URL(sURL); qVjWV$j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5lKJll^2:  
httpConnection.setRequestProperty("User-Agent","NetFox"); %ugHhS!  
String sProperty = "bytes="+nStartPos+"-"; 1 "TVRb  
httpConnection.setRequestProperty("RANGE",sProperty); =6FUNvP#8  
Utility.log(sProperty); z><5R|Gf  
o{v&.z  
(%CZ*L[9Z  
InputStream input = httpConnection.getInputStream(); Ph&urxH@  
//logResponseHead(httpConnection); P27%xV-n>  
3T\l]? z  
`"yxdlXA  
byte[] b = new byte[1024]; {C`GW}s{4  
int nRead; :WGtR\tK  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6SJ"Tni8  
{ P=N$qz$U  
nStartPos += fileAccessI.write(b,0,nRead); $FH18  
//if(nThreadID == 1) K)7zKEp`cj  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MOn,Db$  
} -${DW^txMZ  
+@9gkPQQ-@  
1L7{p>;-dO  
Utility.log("Thread " + nThreadID + " is over!"); C<^YVeG  
bDownOver = true; D\~zS`}  
//nPos = fileAccessI.write (b,0,nRead); }F6<w{|  
} EO|:FcW  
catch(Exception e){e.printStackTrace ();} 9Ywpej*+  
} JuRH>`  
} PW(\4Q\  
0oA{Jix  
qM4c]YIaSl  
//打印回应的头信息 S|V4[ssB  
public void logResponseHead(HttpURLConnection con) [./6At&|  
{ }/dRU${!  
for(int i=1;;i++) ubsSa}$q  
{ #BVtL :x@  
String header=con.getHeaderFieldKey(i); I:&/`K4,x,  
if(header!=null) snM Z0W  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P;ZU-G4@   
Utility.log(header+" : "+con.getHeaderField(header)); QB!~Wh  
else @K223?c8l  
break; [$(%dV6O  
} h-a!q7]l  
} rj ]F87"  
))D:8l@  
.D,p@4  
public void splitterStop() g]@ (E  
{ iO /XhSD  
bStop = true; |LG4=j.l  
} <>xJn{f0c  
Xm2\0=v5;  
j!~l,::$"X  
} Kyt)2p  
hD,:w%M  
in <(g@Zg  
/* $\o {_?}1  
**FileAccess.java vgt]:$  
*//文件访问(定位,写) m~#!  
package NetFox; NvE}eA#  
import java.io.*; UEs7''6RM  
%t=kdc0=_  
2=0DCF;Bv  
public class FileAccessI implements Serializable{ A,-6|&F  
;a=w5,h:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?PA$Ur21lw  
RandomAccessFile oSavedFile; K`&oC8p  
long nPos; N/YWby=H  
75nNh~?)\  
v`J*ixZ7t  
public FileAccessI() throws IOException J2q,7wI#  
{ 4!Z5og1kn  
this("",0); m`#Od^vk  
} vzzE-(\\e  
RpG+>"1]  
JTqDr  
public FileAccessI(String sName,long nPos) throws IOException _iKq~\v2  
{ HD,xY4q&N  
oSavedFile = new RandomAccessFile(sName,"rw"); .Ig+Dj{)  
this.nPos = nPos; cEW0;\$  
oSavedFile.seek(nPos); 2M<R(W!&  
} wS+V]`b  
<H3ezv1M  
q/3ziVd7p  
public synchronized int write(byte[] b,int nStart,int nLen) T lAR.cV  
{ H>Q%"|  
int n = -1; &*G<a3 Q  
try{ j.~!dh$mg  
oSavedFile.write(b,nStart,nLen); (Q[fS:U  
n = nLen; 76tdJ!4Z  
} \y6OUM2y  
catch(IOException e) `.x$7!zLC  
{ .Xm(D>>k  
e.printStackTrace (); ~AY N  
} sb:d>6  
Y3kA?p0  
r`&-9"+  
return n; ?1L.:CS  
}  [=O/1T  
)}Q(Tl\$  
Gir#"5F  
} =U[3PC-N @  
i 8!zu!-0  
Z UKf`m[  
/* Ze< K=Q%(i  
**SiteInfoBean.java UT~a &u  
*/ tqAd$:L  
package NetFox; @3fn)YQ'  
NC&DFJo  
G 6VF>2  
public class SiteInfoBean { &<zd.~N"  
gh`m*@  
`&0Wv0D0  
private String sSiteURL; //Site's URL ]v[|B  
private String sFilePath; //Saved File's Path T|&[7%F3"  
private String sFileName; //Saved File's Name PFUO8>!pA\  
private int nSplitter; //Count of Splited Downloading File }:: S 0l  
l1ZY1#%j  
PcB_oG g  
public SiteInfoBean() f >BWG`  
{//nSplitter的缺省值为5 F4=}}k U  
//default value of nSplitter is 5 |+  N5z  
this("","","",5); )9,  
} ys_`e  
l4T7'U>`  
FZreP.2)!  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vVGDDDz/  
{ _%'},Xd.z  
sSiteURL= sURL; gTRF^knrY  
sFilePath = sPath; ' |-JWH  
sFileName = sName; wf, 7==  
this.nSplitter = nSpiltter; TJE\A)|>g  
6y%0`!  
Y@'8[]=0  
} Gm*X'[\DD  
5cx#SD&5/  
}@if6(0  
public String getSSiteURL() Qf@I)4'  
{ u3Gjg{-N7  
return sSiteURL; A^Kbsc  
} +cb6??H  
.q+0pj  
No2b" G@  
public void setSSiteURL(String value) S9HwIH\m  
{ }68i[v9Njk  
sSiteURL = value; Nn>'^KZNG  
} =PGs{?+&O  
c1X1+b,  
0"~i ^   
public String getSFilePath() "~TA SX_?  
{ ? ` SUQm  
return sFilePath; XMG]Wf^%\<  
} \uss Uv  
)M2F4[vcb  
;Eu3[[V  
public void setSFilePath(String value) R_=6GZH$G  
{ zB yqD$  
sFilePath = value; -i-?.:  
} Z{'i F   
tTd\|  
X.`~>`8  
public String getSFileName() !3T&4t  
{ fM^[7;]7e  
return sFileName; #^+DL]*l  
} "RIZV  
fNGZo  
HR}bbsqxVf  
public void setSFileName(String value) pW4 cX  
{ YBh'EL}P  
sFileName = value; 9@+5LZR  
} 8,dBl!G=  
O12eH  
g+X}c/" .  
public int getNSplitter() |7x\m t  
{ yA47"R  
return nSplitter; 2wF8 P)  
} vv26I  
"Ks,kSEzu  
:1Sl"?xU  
public void setNSplitter(int nCount) ON+J>$[[  
{ jt+iv*2N>  
nSplitter = nCount; )>BHL3@  
} $.]l!cmi%Q  
} XrZ*1V  
V)}rEX   
v%Wx4v@%SE  
/* ,AT[@  
**Utility.java (p%>j0<  
*/ A_KW(;50  
package NetFox; >M&3Y XC  
](|\whI  
0Won9P  
public class Utility { 3G kv4,w<  
k5]j.V2f  
nT2)E&U6%  
public Utility() _UuC,Pl3  
{ qx%}knB  
Hc`A3SMR  
Bj7gQ%>H4  
} irjP>3_e  
m#=z7.XrX  
//线程睡眠 dO%W+K  
public static void sleep(int nSecond) 7 [0L9\xm  
{ sJNFFOz  
try{ $ MC)}l  
Thread.sleep(nSecond); 5atYOep  
} 8_N]e'WUh  
catch(Exception e) .1LCXW=  
{ $8BPlqBIZ  
e.printStackTrace (); i~r l o^  
} z;y:9l  
} 3po:xMY  
|fo0  
//日志 5e WwgA  
public static void log(String sMsg) }l=xiAF  
{ XC+A_"w)  
System.err.println(sMsg); S{3nM<  
} JfPD}w  
-IV]U*4  
++E3]X|  
public static void log(int sMsg) Z@r.pRr'  
{ 6^DR0sO  
System.err.println(sMsg); m4*@o?Ow  
} q:g2Zc'Y~W  
} f7}*X|_Y  
Dl}$pN  
O+ICol  
/* t%8d-+$  
**TestMethod.java j1(D]Z=\  
*/ C`q@X(_   
package NetFox; ?Q&yEGm(  
_Zr.ba  
b".L_Ma1*  
public class TestMethod { rXHv`k y  
N?.%?0l  
9+pmS#>_  
public TestMethod() IH"6? 9nd  
{ ///xx/weblogic60b2_win.exe Nv"EV;$  
try{ )RcL/n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]~3U  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ` He,p -  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $cZUM}@  
fileFetch.start(); +sJrllrE(  
} zen*PeIrA^  
catch(Exception e){e.printStackTrace ();} [ Fz`D/  
4!wR_@W^El  
MuSUKBhM  
} M %Qt|@O  
 E6WA}_  
S.a%  
public static void main(String[] args) XO'l Nb.  
{ .rf" (lM  
new TestMethod(); y8DhOlewQ  
} ZIF49`Y4TF  
} }[xs~! 2F  
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