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http断点续传简单实现(java)

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/* zc)nDyn  
**SiteFileFetch.java {q8|/{;  
*/ L$OZ]  
package NetFox; L QV@]z&  
import java.io.*; -%fj-Y7y  
import java.net.*; }'x)e  
W1"NKg~4  
HLPRTta.  
public class SiteFileFetch extends Thread { U3:|!CC)T  
# 2^H{7  
+yfUB8Xw  
SiteInfoBean siteInfoBean = null; //文件信息Bean ig.Z,R3@r  
long[] nStartPos; //开始位置 @~ke=w6&pe  
long[] nEndPos; //结束位置 ~v2(sRJ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 q`2dL)E  
long nFileLength; //文件长度 .cs x"JC  
boolean bFirst = true; //是否第一次取文件 (!{*@?S  
boolean bStop = false; //停止标志 xJ/)*?@+  
File tmpFile; //文件下载的临时信息 SQK82 /  
DataOutputStream output; //输出到文件的输出流 d<j`=QH  
us|Hb  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) PsNrCe%e  
public SiteFileFetch(SiteInfoBean bean) throws IOException kK4 a;j.#  
{ i3|xdYe$  
siteInfoBean = bean; hIqUidJod  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); u,8)M' UU  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); nD eVYK  
if(tmpFile.exists ()) >uYQt ~s  
{ iKPgiL~  
bFirst = false; d38o*+JCf  
read_nPos(); :B5*?x  
} )HE{`yiLL  
else QjSWl,{ $D  
{ w>X@ ,  
nStartPos = new long[bean.getNSplitter()]; 4pT^ *  
nEndPos = new long[bean.getNSplitter()]; I(R%j]LX&  
} oc,I, v  
l@GJcCufE  
qdpi-*2  
|VaJ70\o  
} ER9{D$  
k6(</uRj  
S"G(_%  
public void run() =6ru%.8U,  
{ 7/hn%obC  
//获得文件长度 &UnhYG{A  
//分割文件 J7",fb  
//实例FileSplitterFetch Wm-$l  
//启动FileSplitterFetch线程 ].J;8}  
//等待子线程返回 y(g]:#  
try{ )ddJ\:  
if(bFirst) L%$ -?O|  
{ n7;jME/!  
nFileLength = getFileSize(); D%3$"4M7!  
if(nFileLength == -1) )s:kQ~+  
{ z0+JMZ/  
System.err.println("File Length is not known!"); `!N}u  
} '/UT0{2;rS  
else if(nFileLength == -2) s|XWw<Sa  
{ dO2?&f  
System.err.println("File is not access!"); B6&[_cht  
} q 6UZ`9&z  
else Heh&;c  
{ pm=O.)g4`  
for(int i=0;i<nStartPos.length;i++) <?IDCOt ?  
{ oh$"?N7n1  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); tik*[1it  
} V#$QKn`;  
for(int i=0;i<nEndPos.length-1;i++) g)Hsd0  
{ xV+\R/)x  
nEndPos = nStartPos[i+1]; Mx, 5  
} +Eb-|dM  
nEndPos[nEndPos.length-1] = nFileLength; tgCp2 `n  
} "4WnDd 5"  
} Ih5Y7<8b~  
#y#TEw,  
<7ANXHuSW  
//启动子线程 ^kcuRJ0*$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yw+]S  
for(int i=0;i<nStartPos.length;i++) vA:ZR=)F  
{ t*Ro2QZ  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cu?6\@cD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'qiAmaX  
nStartPos,nEndPos,i); 5s^vC2$)  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ul N1z  
fileSplitterFetch.start(); N9d^;6;i  
} ?+=,t]`!m  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <!G /&T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8d'/w}GV  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :,p3&2 I  
nEndPos = " + nFileLength); LEnv/t6U  
// fileSplitterFetch[nPos.length-1].start(); @eBo7#Zr  
1r.2bL*~jw  
dbEXl m  
//等待子线程结束 @+M1M 2@Xz  
//int count = 0; -,/6 Wn'j  
//是否结束while循环 rT;l#<#VE  
boolean breakWhile = false; ,ynN801\m  
_G-6G=q  
/J-.K*xKt  
while(!bStop) |QbCFihn  
{ g8Y)90 G  
write_nPos(); Vo{ ~D:)  
Utility.sleep(500); `xv Uq\  
breakWhile = true; zBTxM  
z<A8S=s6n  
U<XfO'XJ  
for(int i=0;i<nStartPos.length;i++) I31Nu{  
{ 7!`1K_v6  
if(!fileSplitterFetch.bDownOver) 0 nI*9  
{ T<nK/lp1t  
breakWhile = false; 4$2HO `@uN  
break; ''9K(p6  
} j4@6`[n:  
} `{w|2 [C3  
if(breakWhile) v%`k*n':  
break; &u"mFweS  
`3K."/N6c  
%y>*9$<pXe  
//count++; >3p8o@:  
//if(count>4) %|/\Qu  
// siteStop(); e5FF'~A%]  
} U[yA`7Zs}  
_8`S&[E?  
k?3mFWc  
System.err.println("文件下载结束!"); ~|{e"!(}  
} buKkm$@w  
catch(Exception e){e.printStackTrace ();} @Py'SH!-  
} rWM5&M  
-ImO y|  
)99^58my  
//获得文件长度 Bz,Xg-k+  
public long getFileSize() W1M Bk[:Q  
{ 4rCw#mVtB  
int nFileLength = -1; ~:C`e4  
try{ NQ '|M  
URL url = new URL(siteInfoBean.getSSiteURL()); SZxnYVY  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $RRh}w\0^  
httpConnection.setRequestProperty("User-Agent","NetFox"); |a0@4 :  
bWCtRli}  
>"zN`  
int responseCode=httpConnection.getResponseCode(); X"f]  
if(responseCode>=400) .)t*!$5=N  
{ $G /p[JG6-  
processErrorCode(responseCode); @Ko}Td&E(  
return -2; //-2 represent access is error l~1l~Gx_&n  
} ZS&+<kGD  
,k:>Z&:  
oC!z+<  
String sHeader; gazX2P[D  
Q`=d5Uvw  
eY:jVYG(  
for(int i=1;;i++) RbA.&=3  
{ 3P'Wk|j  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c/-'^+9  
//Utility.log(in.readLine()); *'@T+$3s  
sHeader=httpConnection.getHeaderFieldKey(i); u3 4.   
if(sHeader!=null) +=kz".$  
{ IV`+B<3  
if(sHeader.equals("Content-Length")) *u>[  
{ '_n$xfH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~f8:sDJ  
break; A22'qgKm@  
} @Rqn&tA8  
} 99Nm?$ g  
else :{#w-oC>6P  
break; qHYoQ.ke  
} ^{O1+7d[.  
} ir;az{T#U  
catch(IOException e){e.printStackTrace ();} ^"J)^3j<  
catch(Exception e){e.printStackTrace ();} 40;4=  
w[;5]z  
|s !7U  
Utility.log(nFileLength); H|d"45J_  
$)j f  
s";9G^:  
return nFileLength; #t&L}=G{%  
} ]n4G]ybK%  
=|3*Y0  
>Cglhsb:N  
//保存下载信息(文件指针位置) Ij7[2V]c  
private void write_nPos() 8SO(pw9  
{ E*UE?4FSw|  
try{ $_W kI^  
output = new DataOutputStream(new FileOutputStream(tmpFile)); jH2_Ekgc;_  
output.writeInt(nStartPos.length); OGnuBK  
for(int i=0;i<nStartPos.length;i++) YGCBDH%6  
{ Cfst)[j  
// output.writeLong(nPos); =zwn3L8fL  
output.writeLong(fileSplitterFetch.nStartPos); C.=[K_  
output.writeLong(fileSplitterFetch.nEndPos); z7O$o/E-*  
} \ UiITP<  
output.close(); 89%#;C  
} J4m2|HK  
catch(IOException e){e.printStackTrace ();} y-a3  
catch(Exception e){e.printStackTrace ();} 2fMKS  
} >B+!fi'SS>  
t`"pn <  
0-I L@Di`F  
//读取保存的下载信息(文件指针位置) 0{.[#!CSk  
private void read_nPos()  D ~t  
{ !s[[X5  
try{ O g!SFg*  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :z%q09.)  
int nCount = input.readInt(); 6{?B`gm7g  
nStartPos = new long[nCount]; 7NQEnAl  
nEndPos = new long[nCount]; 9<1dps=c  
for(int i=0;i<nStartPos.length;i++) Hus.Jfam  
{ AP/#?   
nStartPos = input.readLong(); ;a~ e  
nEndPos = input.readLong(); Ox&]{  
} t,308Z  
input.close(); )cBO_  
} 18G=j@k7  
catch(IOException e){e.printStackTrace ();} 9 kLA57  
catch(Exception e){e.printStackTrace ();} yuq2)  
} klx28/]  
s7 3'h  
Ew*SA  
private void processErrorCode(int nErrorCode) `E8D5'tt  
{ XWq@47FR  
System.err.println("Error Code : " + nErrorCode); `]wk)50BVp  
} LHd9q ^D  
}5lC8{wZ  
K4Hu0  
//停止文件下载 -$cO0RSY  
public void siteStop() i^"!"&tW#  
{ o&#!W(   
bStop = true; m,PiuR>  
for(int i=0;i<nStartPos.length;i++) =&roL7ps  
fileSplitterFetch.splitterStop(); QEc4l[^{.B  
J)P7QTC  
28LYGrB  
} #.@-ng6C  
} 5 N:IH@  
//负责部分文件的抓取 #X qnH  
**FileSplitterFetch.java w L4P-4'  
*/ nG0R1<  
package NetFox; c[a^fu!  
> - U+o.o  
R0YWe  
import java.io.*; y'm5Z-@o6  
import java.net.*; e$o]f"(  
Cm;M; ?  
[Z;ei1l  
public class FileSplitterFetch extends Thread { t {H{xd  
t:*1* ;  
1x^Vv;K  
String sURL; //File URL 5Kw?#  
long nStartPos; //File Snippet Start Position PP8627uP  
long nEndPos; //File Snippet End Position %BF,;(P  
int nThreadID; //Thread's ID }mpFo 2  
boolean bDownOver = false; //Downing is over 4|;Ys-Q  
boolean bStop = false; //Stop identical 1H \  
FileAccessI fileAccessI = null; //File Access interface iAZbh"I  
YFP<^y=  
JJy.)-R  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  Lr0:y o  
{ D.gD4g_O/  
this.sURL = sURL; HJJ; gTj  
this.nStartPos = nStart; &pW2R}  
this.nEndPos = nEnd; 17-B'Gl!<%  
nThreadID = id; \&[(PNl  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;.=]Ar}  
} ehTv@2b  
&z@}9U*6b  
/h8100  
public void run() +QP(ATdM  
{ NuW6~PV  
while(nStartPos < nEndPos && !bStop) J vq)%t8q>  
{ D7=Irz!O\7  
o pTH6a  
X.ecA`0  
try{ #n]K$k>  
URL url = new URL(sURL); S_?sJwM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }46Zfg\T6n  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3n~O&{  
String sProperty = "bytes="+nStartPos+"-"; 6j95>}@  
httpConnection.setRequestProperty("RANGE",sProperty); }42Hhu7j  
Utility.log(sProperty); RK=Pm7L:`y  
i|m8#*Hd  
 \>||  
InputStream input = httpConnection.getInputStream(); &4ndi=.#rg  
//logResponseHead(httpConnection); mZO-^ct4  
LW k/h 1  
'KDt%?24  
byte[] b = new byte[1024]; -fp/3-  
int nRead; BS(jC  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cbl>:ev1h  
{ %7QSBL  
nStartPos += fileAccessI.write(b,0,nRead); QAAuFZs  
//if(nThreadID == 1) En)Ptz#0  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %J Jp/I  
} R+z'6&/ =I  
;M~9Yr=1  
#<X4RJ  
Utility.log("Thread " + nThreadID + " is over!"); (V1;`sI8  
bDownOver = true; ^+~ 5\c*  
//nPos = fileAccessI.write (b,0,nRead); (H"{r  
} :s \zk^h?  
catch(Exception e){e.printStackTrace ();} }ice*3'3  
} $B7c\MR j  
} .)=*Yr M  
iJj!-a:z.  
EIfqRRTA  
//打印回应的头信息 {~w(pAx  
public void logResponseHead(HttpURLConnection con) _>BYUPY  
{ w]nt_xj  
for(int i=1;;i++) `wZ  
{ RN|Bk  
String header=con.getHeaderFieldKey(i); w,up`W7,  
if(header!=null) Ijap%l1I  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (EvYrm4  
Utility.log(header+" : "+con.getHeaderField(header)); :J_UXtx  
else DBG0)=SHy  
break; kvuRT`/  
} yf!7 Q>_G^  
} %hN(79:g  
EZ:? (|h  
Y652&{>q  
public void splitterStop() wVFa51a)yy  
{ dNY'uv&Y  
bStop = true; {to(?`Y  
} M$.bC0}T  
* xmC`oP  
|vm-(HY!  
} :3XvHL0rx  
H C,5j)1  
xf/K+  
/* uD?RL~M  
**FileAccess.java EpKZ.lCU  
*//文件访问(定位,写) \!30t1EZ  
package NetFox; -s!J3DB  
import java.io.*; 3 !8#wn  
GD)paTwO<  
)B +o F7  
public class FileAccessI implements Serializable{ qoH:_o8ClO  
7O k-T10  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `GBJa k  
RandomAccessFile oSavedFile; ,/GFD[SQ  
long nPos; !vRN'/(Vyu  
rir,|y,  
jD"nEp-  
public FileAccessI() throws IOException @%2crJnkS  
{ @(oY.PeS<z  
this("",0); p/Q< VV  
} BeQ'\#q,  
g.Qn,l]X/p  
;<[!;8  
public FileAccessI(String sName,long nPos) throws IOException xu"-Uj1  
{ !`7evV:  
oSavedFile = new RandomAccessFile(sName,"rw"); dc4XX5Z  
this.nPos = nPos; ME]7e^  
oSavedFile.seek(nPos); 0PFC %x  
} #K@!jh)y^  
"N_@q2zF  
Iurz?dt4w  
public synchronized int write(byte[] b,int nStart,int nLen) mZ? jpnd  
{ 2?Ryk`2i)  
int n = -1; ]j,o!|rx7  
try{ g8&& W_BI  
oSavedFile.write(b,nStart,nLen); g'T L`=O  
n = nLen; I]5){Q" S  
} #Pz'-lo  
catch(IOException e) H(- -hG5}  
{ ow 6\j:$?  
e.printStackTrace (); }*%=C!m4R!  
} J0e^v  
oNl-! W   
K iXD1Zpz  
return n; 0QquxYYw,  
} "30=!k  
2uY:p=DxG9  
ak3WER|f#  
} ZJGIib  
%jq R^F:J  
v6aMYmenBH  
/* jL5O{R[ x:  
**SiteInfoBean.java Vu~fF@ |  
*/ }V.fY3J-  
package NetFox; -~\7ZRP8  
6rG7/  
"FGgem%9  
public class SiteInfoBean { wT;;B=u}G  
#\Q)7pgi.  
9S'\&mRl  
private String sSiteURL; //Site's URL P??pWzb6HH  
private String sFilePath; //Saved File's Path kaEu\@%n  
private String sFileName; //Saved File's Name .g}Y! l  
private int nSplitter; //Count of Splited Downloading File 1ATH$x  
tC f@v'1t  
[vY)y\W{  
public SiteInfoBean() b^8"EBo  
{//nSplitter的缺省值为5 @.`HvS  
//default value of nSplitter is 5 (lit^v,9  
this("","","",5); 3+U2oI:I  
} >i61+uzEd+  
ov!L8 9`[u  
,<OS: ]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #&{)`+!"  
{ OQuTM[W  
sSiteURL= sURL; =PLy^%  
sFilePath = sPath; g8"{smP/  
sFileName = sName; mn{R>  
this.nSplitter = nSpiltter; X)9|ZF2`  
W"xRf0\V  
Hpp;dG  
} 9x8Ai  
!$o9:[B  
<lPHeO<^]  
public String getSSiteURL() aO\@5i_r  
{ Gh'{O/F4*  
return sSiteURL; bV@5B#] 2R  
} `5~<)  
O} lqY?0*  
)7rMevF(xJ  
public void setSSiteURL(String value) Qm?o^%a  
{ zjx'nK{eI  
sSiteURL = value; 1;MUemnx`  
} UZc{ Av  
cC,gd\}M  
(W`=`]!  
public String getSFilePath() ;wr]_@<~  
{ :4238J8  
return sFilePath; >LR+dShG  
} kca  Y  
w{ x=e  
iJu$&u  
public void setSFilePath(String value) RveMz$Yy  
{ 'cbD;+YH  
sFilePath = value; /lvH p  
} Aa%ks+1  
/#?i+z   
]p~,C*UH0  
public String getSFileName() JvLa@E)  
{ r\{; ~V  
return sFileName; gB#$"mq,  
} d4-cZw}+  
(KG>lTdN  
B3Esfk  
public void setSFileName(String value) 3sGe#s%  
{ ,b8B)VZ?  
sFileName = value; = P {]3K  
} -U_<:  
jvos)$;L-  
30/(  
public int getNSplitter()  !.k  
{ )u'("  
return nSplitter; 0IjQqI  
} %!1:BQ,p,i  
Nb;Yti@Y.  
niN$!k+Jr  
public void setNSplitter(int nCount) =Wk!mGc  
{ >?A3;O]  
nSplitter = nCount; E>?T<!r~j  
} x:Kca3pv_  
} 5 gbJTh<JU  
# S4{,  
l*yJU3PW  
/* C"ZCX6p+$  
**Utility.java Lw.N3!e[  
*/ SuW_[6 ]  
package NetFox; `795 K8  
O<h`[1eUjS  
l4d2 i;4BK  
public class Utility { R3$e q )  
`W[oLQ  
k^.9;FmQ  
public Utility() ,*V{g pC7  
{ 5X-cDY*|  
l>M&S^/s j  
ZUMzWK5Th  
} ^@`dsll  
A_@#V)D2  
//线程睡眠 (byFr9z  
public static void sleep(int nSecond) \^3\_T&6  
{ T;}pMRd%  
try{ ZuF-$]oL&  
Thread.sleep(nSecond); ([ xYOxcp5  
} t{K1ht$[:  
catch(Exception e) mi3yiR  
{ m`-{ V<(M  
e.printStackTrace (); avk0pY(n  
} b07 MTDFH7  
} nlK"2/W  
r!etj3  
//日志 [3rvRJ.  
public static void log(String sMsg) V4Ql6vg_f  
{ dM7-,9Vc  
System.err.println(sMsg); [>4Ou^=1  
} bY;ah;<  
dGcG7*EX  
h5ST`jZ  
public static void log(int sMsg) $} 7/mS@c  
{  #IyxH$  
System.err.println(sMsg); j#0@%d  
} pNI=HHx  
} H{`S/>)[   
s&!g )  
4?,N;Q  
/* 2|Hq[c=~  
**TestMethod.java B9n$8QS  
*/ {KE858  
package NetFox; =x9zy]  
p^A9iieHp=  
u-At k-2M  
public class TestMethod { WeE>4>^  
*K'(t  
ZPY#<^WOzr  
public TestMethod() vWcU+GBZI  
{ ///xx/weblogic60b2_win.exe ?x"<0k1g  
try{ tD.md _E  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kA{[k  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iXMs*G cK  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4WZ:zr N  
fileFetch.start(); vu;pILN  
} V,fSn:8%M  
catch(Exception e){e.printStackTrace ();} B_anO{3$4  
yNP M-  
#)2'I`_E  
} lphQZ{8  
kcVEE)zb  
L\XnTL{  
public static void main(String[] args) aRdzXq#x  
{ 9sifc<za  
new TestMethod(); [84ss;.$  
} &p%0cjg"Q  
} %Iw6oG  
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