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http断点续传简单实现(java)

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/* _64<[2  
**SiteFileFetch.java JVq`v#8  
*/ hO..j  
package NetFox; JTdcL mL  
import java.io.*; #|;;>YnZ   
import java.net.*; , %$Cfu  
.Dt.7G  
F0tx.]uS  
public class SiteFileFetch extends Thread { /[=U$=uH  
szas(7kDS  
G^A}T3  
SiteInfoBean siteInfoBean = null; //文件信息Bean bw*D!mm,  
long[] nStartPos; //开始位置 f ( ug3(j  
long[] nEndPos; //结束位置 yPT\9"/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 U~_G *0  
long nFileLength; //文件长度 ](SqLTB+?  
boolean bFirst = true; //是否第一次取文件 of0 hJR  
boolean bStop = false; //停止标志 Ep8 y  
File tmpFile; //文件下载的临时信息 }080=E  
DataOutputStream output; //输出到文件的输出流 ;;<[_gp,E  
?Y'r=Q{w  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #r;uM+  
public SiteFileFetch(SiteInfoBean bean) throws IOException ~RIa),GVX  
{ mmBZ}V+&=  
siteInfoBean = bean; Ahrtl6@AS  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "Tc[1{eI  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 1j\wvPLr  
if(tmpFile.exists ()) _[8sL^  
{ X DAwE  
bFirst = false; h f9yK6  
read_nPos(); zZI7p[A[3  
} &~sk7iGi  
else A]AM|2 D  
{  Sn-D|Z  
nStartPos = new long[bean.getNSplitter()]; (5&l<u"K~  
nEndPos = new long[bean.getNSplitter()]; <7yn:  
} VIg=| Oe),  
nQM7@"R  
.9KW| (uW  
]-tAgNzl%  
} C^!ej"  
p="K4E8~H  
kJ:zMVN  
public void run() 31n|ScXv  
{ Z'|A>4\  
//获得文件长度 {#J1D*?$"  
//分割文件 W.VyH|?  
//实例FileSplitterFetch aIABx!83>  
//启动FileSplitterFetch线程 {GM8}M~D&  
//等待子线程返回 1PdxoRa4=  
try{ G?QU|<mj<  
if(bFirst) &4-rDR,  
{ AC9#!# OGB  
nFileLength = getFileSize(); {uuvgFC  
if(nFileLength == -1) @dp1bkU  
{ =| M[JPr  
System.err.println("File Length is not known!"); b1`(f"&l  
} 1O]27"9  
else if(nFileLength == -2) (Jb[_d*  
{ Z,bvD'u  
System.err.println("File is not access!"); mQ]wLPP{1  
} Q8 r 7  
else ljo^ 2  
{ ,0R2k `m!  
for(int i=0;i<nStartPos.length;i++) Ood'kAH1B  
{ qg;f h]j%  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ET7(n0*P}]  
} HN*w(bROr  
for(int i=0;i<nEndPos.length-1;i++) K?o}B  
{ d.3O1TXK  
nEndPos = nStartPos[i+1]; jW-j+ WGSM  
}  T8i9  
nEndPos[nEndPos.length-1] = nFileLength; (]mh}=:KDg  
} i-EFq@xl  
} Sr`gQ#b@r}  
7gV"pa  
[[PUK{P0  
//启动子线程 RJ_ratKN*g  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gd~Xvw,u  
for(int i=0;i<nStartPos.length;i++) $3! j1  
{ 6 1Nj&1Ze  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7FVu [Qu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }V3p <  
nStartPos,nEndPos,i); \"qXlTQ1_9  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?zKVXK7}0  
fileSplitterFetch.start(); rSD!u0c [  
} _gY so]S^B  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -P5VE0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z3G>DF:$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }B_n}<tjD  
nEndPos = " + nFileLength); '!!w|k d  
// fileSplitterFetch[nPos.length-1].start(); EvMhNq~y5  
DsqsMlB{  
`OnN12`  
//等待子线程结束 ehXj.z  
//int count = 0; LS?hb)7  
//是否结束while循环 w?.0r6j  
boolean breakWhile = false; HB\y [:E  
f3-=?Z  
Zb7KHKO{  
while(!bStop) {t[j>_MYw  
{ ]?^m;~MQZ  
write_nPos(); K2L+tw  
Utility.sleep(500); [S":~3^B6  
breakWhile = true; [Y*p I&f  
Y{@ez  
/g'F+{v  
for(int i=0;i<nStartPos.length;i++) ^MUtmzh  
{ g`gH]W FcG  
if(!fileSplitterFetch.bDownOver) b}o^ ?NtA  
{ @y9_\mX!s  
breakWhile = false; x!MYIaZ7  
break; " 9 h]P^  
} hp,bfcM  
} 3Zdkf]Gh  
if(breakWhile) 2@1A,  
break; //>f#8Ho  
,S:LhgSP  
EdE,K1gD  
//count++; 2>.B*P  
//if(count>4) +l2{EiQw  
// siteStop(); D +N{'d?+  
} yFshV\   
a*NcL(OC  
}X)mZyM[  
System.err.println("文件下载结束!"); 7:R8QS9  
} =5oE|F%  
catch(Exception e){e.printStackTrace ();} Q~#udEajI  
} tV9nC   
OCa74)(  
=\ iV=1iB  
//获得文件长度 xYRN~nr  
public long getFileSize() cMsm[D{b  
{ u8v;O}#  
int nFileLength = -1; TPt<(-}W  
try{ lDnF(  
URL url = new URL(siteInfoBean.getSSiteURL()); >>Z.]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "e0$/WQ6J  
httpConnection.setRequestProperty("User-Agent","NetFox"); i!LEA/"V  
xJa  
'0[D-jEr  
int responseCode=httpConnection.getResponseCode(); `6)GjZh^  
if(responseCode>=400) .EM0R\q  
{ t4/d1qW0  
processErrorCode(responseCode); oa?bOm  
return -2; //-2 represent access is error HJo&snT3  
} fr#Y<=Jo  
`|P fa  
{Xb 6wQ"  
String sHeader; 5 >S #ew  
26.),a  
3} @3pVS  
for(int i=1;;i++) -~ \R.<+  
{ gHpA@jdC*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); : W6`{Z  
//Utility.log(in.readLine()); 8/F}vfKEN  
sHeader=httpConnection.getHeaderFieldKey(i); cVYDO*N2T  
if(sHeader!=null) Tw *:Vw  
{ Q>Voa&tYn  
if(sHeader.equals("Content-Length")) ?~X*\  
{ bnHQvCO3$  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VPW@y  
break; (8T36pt~  
} <qJI]P  
} E-gI'qG\(  
else J<hqF4z  
break; H@Yj  
} omz%:'m`~  
} .TZ0F xW  
catch(IOException e){e.printStackTrace ();} hWc`4xdl  
catch(Exception e){e.printStackTrace ();} H4RqOI  
%87D(h!.I4  
)S?.YCv?  
Utility.log(nFileLength); )(bAi  
%G6Q+LMwm  
QFekj@  
return nFileLength; zplAH!s5''  
} &[ oW"Q{  
rtM29~c>@  
M2Q*#U>6r  
//保存下载信息(文件指针位置) !m]_tB  
private void write_nPos() i ZU 1w7Z  
{ j(aok5:e  
try{ d23;c )'  
output = new DataOutputStream(new FileOutputStream(tmpFile)); S?Y%}  
output.writeInt(nStartPos.length); ,I|3.4z  
for(int i=0;i<nStartPos.length;i++) 9U]3B)h%m  
{ cG)U01/"  
// output.writeLong(nPos);  " fXs!  
output.writeLong(fileSplitterFetch.nStartPos); !)r1zSY"g  
output.writeLong(fileSplitterFetch.nEndPos); xaN[ru@  
} e^=b#!}-5:  
output.close(); c`Q#4e]%_  
} Z Jgy!)1n  
catch(IOException e){e.printStackTrace ();} aM5Hp>'nI  
catch(Exception e){e.printStackTrace ();} \+Nn>wW.  
} F+<e9[  
S1I# qb  
Mg~62u  
//读取保存的下载信息(文件指针位置) <D`VFSEJ  
private void read_nPos() OC6v%@xa  
{ 1xTNrLW  
try{ )z\ 73|w  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ooA%/  
int nCount = input.readInt(); bZ SaL^^(  
nStartPos = new long[nCount]; ?Gnx!3Q  
nEndPos = new long[nCount]; $y_P14  
for(int i=0;i<nStartPos.length;i++) \=2<< iv  
{ wiP )"g.t  
nStartPos = input.readLong(); =/m$ayG  
nEndPos = input.readLong(); ]KM3G  
} ':d9FzGKa  
input.close(); (zml704dI)  
} F\2<q$Zn+  
catch(IOException e){e.printStackTrace ();} *@eZt*_  
catch(Exception e){e.printStackTrace ();} rI#,FZ  
} jaL#  
{k uC+~R  
*J3Z.fq%:i  
private void processErrorCode(int nErrorCode) KY+BXGW*  
{ M@=VIrX,m  
System.err.println("Error Code : " + nErrorCode); "IJ 9vXI  
} PTH'-G  
B-oQjr-  
:yFmCLZaQ  
//停止文件下载 FO:k >F  
public void siteStop() =JE5/  
{ B8 r#o=q1  
bStop = true; [5-3PuT&9  
for(int i=0;i<nStartPos.length;i++) Z#zXary5s  
fileSplitterFetch.splitterStop(); AP9>_0=  
J\E?rT  
)@_5}8  
} AvcN,  
} a{\<L/\  
//负责部分文件的抓取 O4oI&i 7  
**FileSplitterFetch.java ,HwOMoP7  
*/ }K|40oO5  
package NetFox; }8dS[-.  
Rg7~?b-  
 zt2#6v  
import java.io.*; !"SuE)WM  
import java.net.*; 5GwzG<.\^_  
Vi>`g{\  
"qhQJql  
public class FileSplitterFetch extends Thread { UF;iw  
;uaZp.<um&  
-Q" N;&'[&  
String sURL; //File URL vt(cC) )  
long nStartPos; //File Snippet Start Position )|B3TjH C  
long nEndPos; //File Snippet End Position ~y>NJM>1  
int nThreadID; //Thread's ID ok/{ w  
boolean bDownOver = false; //Downing is over Fjw+D1q.  
boolean bStop = false; //Stop identical "f4atuuXa  
FileAccessI fileAccessI = null; //File Access interface Jj7he(!_1  
%Wa. 2s  
sh;>6xB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RP%7M8V){B  
{ c}mWAZ=wF  
this.sURL = sURL; li&&[=6A  
this.nStartPos = nStart; ?y2v?h"  
this.nEndPos = nEnd; o,_R;'\E[a  
nThreadID = id; _e$T'*q  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5^C.}/#>F  
} ;fZ9:WB  
e2"gzZ4;g  
uol EX+  
public void run() Ax'o|RE)x  
{ 6Jd.Eg ~A7  
while(nStartPos < nEndPos && !bStop) =v7%IRP5  
{ Itv}TK eF  
;0-Y),  
dr]Pns9  
try{ 5'S~PQka*  
URL url = new URL(sURL); */y (~O6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VTJxVYE  
httpConnection.setRequestProperty("User-Agent","NetFox"); i]}`e>fF  
String sProperty = "bytes="+nStartPos+"-"; i2 G.<(3O  
httpConnection.setRequestProperty("RANGE",sProperty); FwqaWEk  
Utility.log(sProperty); evGUl~</~  
LyG&FOf?  
% jSB9  
InputStream input = httpConnection.getInputStream(); Ms14]M[\  
//logResponseHead(httpConnection); 2dnyIgi  
rLp (}^  
UHFI4{Wz  
byte[] b = new byte[1024]; cc{^0JT  
int nRead; vY!'@W  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pd}Cg'}X  
{ s_%KWkS  
nStartPos += fileAccessI.write(b,0,nRead); +AYB0`X)  
//if(nThreadID == 1) 4}Dfi5:   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zy'cf5k2  
} 4^_'LiX3[  
P~M<OUg  
=H;F{J "  
Utility.log("Thread " + nThreadID + " is over!"); {3eg4j.Z  
bDownOver = true; ]i Yp  
//nPos = fileAccessI.write (b,0,nRead); A^vvw~!d  
} [^0 S#,L  
catch(Exception e){e.printStackTrace ();} T_Cj=>L  
} SSysOeD+  
} Qm>2,={h  
`&URd&ouJD  
|OBh:d_B]  
//打印回应的头信息 ;|pw;-  
public void logResponseHead(HttpURLConnection con) 8 DPn5E#M1  
{ @7`=0;g  
for(int i=1;;i++) U# U*^#  
{ U?=-V8#M|  
String header=con.getHeaderFieldKey(i); +d=w%r)  
if(header!=null) fVz0H1\J&  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #j4RX:T*[  
Utility.log(header+" : "+con.getHeaderField(header)); S#*aB2ZS  
else  w\y)  
break; b=XXp`h~a  
} 65U&P5W  
} mr>dZ)  
@ RP?)*8}&  
2 2@w:  
public void splitterStop() 7gE/g`"#  
{ 3jjV bm  
bStop = true; .4[M7)  
} [F+*e=wjN>  
} p `A>  
rA /T>ZM  
} X#Hl<d2  
ZuT5}XxF  
#|K5ma  
/* !q 9PO  
**FileAccess.java 7M<co,"  
*//文件访问(定位,写) $l_\9J913  
package NetFox; <xUX&J=;  
import java.io.*; L[tq@[(IJ  
{_ {zs!r  
Dlg9PyQ  
public class FileAccessI implements Serializable{ BBa!l e9P  
Hb\['VhzM  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KM/c^ a4V  
RandomAccessFile oSavedFile; OlM3G^1e1  
long nPos; Bi7&yS5V  
EzU3'x  
@PV3G KJ  
public FileAccessI() throws IOException ^e--4B9|  
{ iN1_ T  
this("",0); 8;O/x  
} "] ]aF1  
6L3i   
>aT~ G!y  
public FileAccessI(String sName,long nPos) throws IOException a}[rk*QmZ  
{ ?~<NyJHN%  
oSavedFile = new RandomAccessFile(sName,"rw"); 6t3Zi:=I  
this.nPos = nPos; =m 6<H  
oSavedFile.seek(nPos); \"b'Z2g  
} xn anca  
Tr, zV  
.gY=<bG/fA  
public synchronized int write(byte[] b,int nStart,int nLen) V!QC.D<  
{ 8zQN[[#n  
int n = -1; )B"E+Q'h{7  
try{ mp8Zb&Ggb  
oSavedFile.write(b,nStart,nLen); ?;ZnD(4?  
n = nLen; [= Xb*~  
} w!OYH1ds]_  
catch(IOException e) IEY\l{s  
{ S7b7zJ8A  
e.printStackTrace (); zZP&`#TAy  
} 7h`t-6<!q  
`o21f{1]X&  
T-Yb|@4  
return n; y 7z)lBy\  
} 2yVQqwQ m  
9[h8Dy  
Zi<(>@z2  
} U5[r&Y D  
dv?t;D@p!  
AJ z 1    
/* M,we,!B0  
**SiteInfoBean.java l=C|4@  
*/ j|@8VxZ  
package NetFox;  p]jG ,S  
@{ L|&Mk!  
n<ecVFft  
public class SiteInfoBean { k0 D):  
le6eorK8  
#4V->I  
private String sSiteURL; //Site's URL seb/rxb  
private String sFilePath; //Saved File's Path Gn;^]8d  
private String sFileName; //Saved File's Name C|]Zpn#{K  
private int nSplitter; //Count of Splited Downloading File ^G "Qp8 "  
MR zY<MD  
&UAYYH  
public SiteInfoBean() :0p$r pJP  
{//nSplitter的缺省值为5 CHDt^(oa!B  
//default value of nSplitter is 5 4wx{i6  
this("","","",5); U-D00l7C  
} c/%GfB[w0  
/< Dtu UM  
#-l+c u{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fn8|@)J  
{ 'fZ\uMdTx  
sSiteURL= sURL; ^~s!*T)\  
sFilePath = sPath; NleMZ  
sFileName = sName; ITD&w g  
this.nSplitter = nSpiltter; C%#u2C2  
j%gle%_  
n^<J@uC  
} bpa'`sf  
Lc(eY{CY  
M3eFG@,  
public String getSSiteURL() Kp19dp}'b  
{ FJFO0Hb6  
return sSiteURL; E0.o/3Gw6  
} 9}+X#ma.Nc  
I~nz~U:ak  
{9{PU&?(  
public void setSSiteURL(String value) ^OK;swDW  
{ A.(e=;0bu  
sSiteURL = value; HE0m#  
} 83VFBY2q  
i/ PL!'oq  
onm" 7JsO'  
public String getSFilePath() CtZOIx.;|  
{ a'O-0]g,  
return sFilePath; u1>WG?/`  
} h+Y>\Cxg  
u(8dsg R  
UK)wV  
public void setSFilePath(String value) [kMWsiZ  
{ 1v*N]}`HU  
sFilePath = value; #k,.xMJ~  
} z'\BZ5riX<  
Q x&7Ceu"  
uH#X:Vne  
public String getSFileName() =Z..&H5i  
{ "BIhd*K[~  
return sFileName; =&~ K;=:  
} @9l$j Z~x  
X]dN1/_  
w=^~M[%w  
public void setSFileName(String value) )k]{FM  
{ E:[!)UG|y  
sFileName = value; 5?|y%YH;R\  
} tH:?aP*2  
SZ:R~4 A  
VBW][f  
public int getNSplitter() "V5_B^Gzb]  
{ Q |hBGH9:B  
return nSplitter; Q8_5g$X\  
} c?6(mU\x  
i_nUyH%b  
@6-3D/=  
public void setNSplitter(int nCount) &a6-+r  
{ G]dHYxG  
nSplitter = nCount; 0*j\i@  
} 5f75r  
} xXJzE|)1h!  
`W7;-  
sosIu  
/* )&-n-m@E  
**Utility.java c~d*SDca  
*/ ZIc-^&`r=  
package NetFox; ]SN5 &S  
2\gbciJ[{(  
J3'0^JP*  
public class Utility { r^Soqom3  
@[1,i~H  
2 ]r5e;  
public Utility() i,L"%q)C  
{ la_  
R^.c  
X*e:MRw[  
} V3axwg_  
S Z &[o&H  
//线程睡眠 ]agdVr^  
public static void sleep(int nSecond) MN>U jFA  
{ o Y<vKs^  
try{ YLV$#a3  
Thread.sleep(nSecond); ON"V`_dq+M  
} .o8pC  
catch(Exception e) 5'xZ9K  
{ s ZokiFJ  
e.printStackTrace (); U* T :p>&  
} {[+Q\<  
} ]O~/k~f  
?!bWUVC)_  
//日志 S7CD#Y[s  
public static void log(String sMsg) 1 EHNg<J(  
{ _3gF~qr  
System.err.println(sMsg); a0  w  
} r\|"j8  
o5NrDDH  
VF9-&HuC  
public static void log(int sMsg) \0l"9 B.  
{ zrur-i$N+  
System.err.println(sMsg); JI92Dc*o  
} a#,lf9M  
} 6EG`0h6  
e1K{*h  
iS28p  
/* 3a,7lTUuB  
**TestMethod.java )W![TIp  
*/ 8f#&CC!L  
package NetFox; s ,GGO3^  
+' ?axv6e  
]F,v#6qi  
public class TestMethod { O.P:~  
%:.00F([r  
$RV'DQO  
public TestMethod() D,'@b+B[  
{ ///xx/weblogic60b2_win.exe lD)QB!*v  
try{ ZD]5"oHY  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E+E.z?>S  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uY=}w"Db  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nc:>]  
fileFetch.start(); dD"o~iEC  
} uEkUK|  
catch(Exception e){e.printStackTrace ();} qnR{'d  
eVbaxL!Q^  
tr\}lfK%  
} u-E*_% y  
g4*]R>f  
Flzl,3rW4  
public static void main(String[] args) hSD uByoi  
{ d.uJ}=|  
new TestMethod(); |^E# cI  
} gb_k^wg~1'  
} ryp@<}A]!d  
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