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http断点续传简单实现(java)

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/* 89WuxCFS  
**SiteFileFetch.java q/]tJ{FI  
*/ b cOX/  
package NetFox; rPQ$e!m1Ee  
import java.io.*; F@?QVdY1q7  
import java.net.*; + J_W}G  
,E/vHI8  
!&#CEF@J  
public class SiteFileFetch extends Thread { Ef7 Kx49I  
654PW9{(  
Z3[,Xw  
SiteInfoBean siteInfoBean = null; //文件信息Bean D@\97t+  
long[] nStartPos; //开始位置 o6{XT.z5qx  
long[] nEndPos; //结束位置 c5Offnq'1  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {\ .2h  
long nFileLength; //文件长度 2b!b-  
boolean bFirst = true; //是否第一次取文件 ZW,PZ<  
boolean bStop = false; //停止标志 _&yQW&vH#  
File tmpFile; //文件下载的临时信息 QAu^]1;  
DataOutputStream output; //输出到文件的输出流 k"AY7vq@!P  
'X`\vTxB  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) hI/p9 `w  
public SiteFileFetch(SiteInfoBean bean) throws IOException ,(lD5iN  
{ Q}I. UG_  
siteInfoBean = bean; ;M}bQ88  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); H#6J7\xcS  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !n !~Bw  
if(tmpFile.exists ()) smk0*m4  
{ Ot v{#bB$  
bFirst = false; 4;%=ohD:!  
read_nPos(); >O~xu^N?  
} -[+FVvS  
else :@Q_oyWE8  
{ d[ {=/~0  
nStartPos = new long[bean.getNSplitter()]; xXLKL6F(\  
nEndPos = new long[bean.getNSplitter()]; nar=\cs~g  
} cbS8~Xmj  
}_u )3X.O  
$KtMv +m"  
.t\ Yv/|`  
} igz&7U8gg  
NH|v`rO  
ysvn*9h+&  
public void run() >2N` l  
{ .llAiv  
//获得文件长度 rJZ-/]Xf!6  
//分割文件 [D /q%  
//实例FileSplitterFetch mz/KGZ5t  
//启动FileSplitterFetch线程 |n]^gTJt  
//等待子线程返回 k%c ?$n"  
try{ z#O{rwnl  
if(bFirst) Be-gGJG  
{ =(zk-J<nY  
nFileLength = getFileSize(); `(16_a  
if(nFileLength == -1) G.c s-f  
{ 3DgI.V6un  
System.err.println("File Length is not known!"); N[=nh)m7b  
} 6I 2`m(5  
else if(nFileLength == -2) k%uRG_  
{ g,x$z~zU{  
System.err.println("File is not access!"); RU[{!E  
} I7]45pF  
else mVk:[ }l6  
{ a#KxjVM  
for(int i=0;i<nStartPos.length;i++) nj)M$'  
{ k98--kc5  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \#~~,k 6f  
} gNe{P~ $=  
for(int i=0;i<nEndPos.length-1;i++) !L>'g  
{ BXLhi(.s  
nEndPos = nStartPos[i+1]; |nMbf  
} j^:\a\-1  
nEndPos[nEndPos.length-1] = nFileLength; RkC?(p  
} aiUn bP  
} &XN*T.Y`  
[NC^v.[1[  
5E~][. d  
//启动子线程 V$^x]z  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wxvt:= =  
for(int i=0;i<nStartPos.length;i++) T,jxIFrF  
{ ,ad~ 6.Z_)  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0wxQ,PI1'  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "<bL-k*H)  
nStartPos,nEndPos,i); IHf A;&b  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -3ha LdRk6  
fileSplitterFetch.start(); 0]NjsOU =  
} A9F&XF7{  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &>sG x K  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Jtc?p{  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sp'q=^t  
nEndPos = " + nFileLength); '(I"54W  
// fileSplitterFetch[nPos.length-1].start(); B>-Iv _  
} %rF}>$A  
0p&:9|'z  
//等待子线程结束 ])0&el3-  
//int count = 0; >>K) 4HYID  
//是否结束while循环 yBq4~b~[  
boolean breakWhile = false; P0UMMn\-#  
awo=%vJ&  
| u36-  
while(!bStop) mrk Q20D  
{ 3^ wJ4=^  
write_nPos(); 6lsU/`.  
Utility.sleep(500); SlsMMD  
breakWhile = true; k' pu%nWN  
h&.9Q{D  
w QwY_ _  
for(int i=0;i<nStartPos.length;i++) N4'b]:`n  
{ vy6NH5Q  
if(!fileSplitterFetch.bDownOver) hF!yp7l;  
{ p8o%H-Xk  
breakWhile = false; }?8KFe7U  
break; M[HPHNsA&  
} $ 'HiNP {c  
} {h|3P/?7  
if(breakWhile) ;%Jp@'46  
break; QMHeU>  
 m ,qU})  
69\0$O  
//count++; !=I:Uc-Y  
//if(count>4) pO=bcs8Z  
// siteStop(); ,tmo6D62  
} I0GL/a 4s  
B% BO  
kRZ(  
System.err.println("文件下载结束!"); !X*L<)=nh  
} rDm>Rm=  
catch(Exception e){e.printStackTrace ();} Ab8~'<F$B  
} G }TT-  
.r[J} O"  
w{#%&e(q"  
//获得文件长度 6R dfF$f  
public long getFileSize() ()3+! };  
{ T\. 8og  
int nFileLength = -1; E=HS'XKu[K  
try{ }MuXN<DDb  
URL url = new URL(siteInfoBean.getSSiteURL()); fJC)>doM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mp"] =  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ypha{d  
c$@,*c 0n  
li,kW`j+t  
int responseCode=httpConnection.getResponseCode(); eAm7*2  
if(responseCode>=400) &Lk@Xq1  
{ Sg')w1  
processErrorCode(responseCode); 32YE%  
return -2; //-2 represent access is error {tF=c0Z  
} e7pN9tXGf  
B_c(3n-"  
(;C_>EL&u  
String sHeader; \MK)dj5uUJ  
.#rI9op  
'HPw5 L  
for(int i=1;;i++) z}OY'}sk8  
{ &!KJrQ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); # |w,^tV  
//Utility.log(in.readLine()); p^\>{  
sHeader=httpConnection.getHeaderFieldKey(i); JnV$)EYi  
if(sHeader!=null) - stSl*  
{  //K]zu  
if(sHeader.equals("Content-Length")) !Z<Z"R/  
{ w[:5uo(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ra$_#HY  
break; tJ2l_M^  
} 69O?sIk  
} 2zArAch  
else 8t9sdqM/C  
break; \`|,wLgH  
} &hjrJ/'^  
} ax7u b  
catch(IOException e){e.printStackTrace ();} ft:/-$&H  
catch(Exception e){e.printStackTrace ();} WNlWigwYl  
ls 'QfJm  
C @hnT<e  
Utility.log(nFileLength); 6Q>:g"_  
;2#HM^Mu  
ax'Dp{Q  
return nFileLength; LTBqXh  
} t~,!a?S7  
:,]%W $f=  
tul5:}x3  
//保存下载信息(文件指针位置) - uliND  
private void write_nPos() |~#!e}L(  
{ ''v_8sv  
try{ h#;fBQ]   
output = new DataOutputStream(new FileOutputStream(tmpFile)); \AkeC6[D  
output.writeInt(nStartPos.length); AO>K 6{  
for(int i=0;i<nStartPos.length;i++) ;y4 "wBX  
{ [4PG_k[uTJ  
// output.writeLong(nPos); m' z<d  
output.writeLong(fileSplitterFetch.nStartPos); l&;#`\s!V  
output.writeLong(fileSplitterFetch.nEndPos); k3^S^Bv\  
} sL+/Eeb` c  
output.close(); Tet,mzVuu  
} PNg,bcl  
catch(IOException e){e.printStackTrace ();} cnhYrX^  
catch(Exception e){e.printStackTrace ();} Kax85)9u  
} b`18y cVME  
i#(T?=VPcy  
cz&FOP+!  
//读取保存的下载信息(文件指针位置) &ATjDbW*(  
private void read_nPos() t4F1[P  
{ *gVRMSrx4  
try{ ]U'KYrh  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A3M)yWq  
int nCount = input.readInt(); J} %&;uv  
nStartPos = new long[nCount]; tw\/1wa.  
nEndPos = new long[nCount]; H[!by)H  
for(int i=0;i<nStartPos.length;i++) *<s|WLMG  
{ 611:eLyy&l  
nStartPos = input.readLong(); spd>.Cm`  
nEndPos = input.readLong(); won%(n,HT  
} a?\ Au  
input.close(); ECU:3KH>MF  
} Y/)>\  
catch(IOException e){e.printStackTrace ();} WAkKbqJV  
catch(Exception e){e.printStackTrace ();} Sf lHSMFw  
} FW=oP>f]w  
:);GeZ  
95?$O~I  
private void processErrorCode(int nErrorCode) 7lf* vqG  
{ e"[o2=v;5  
System.err.println("Error Code : " + nErrorCode); sq-[<ryk  
} vKol@7%N  
9M<qk si  
a:v&pj+|<  
//停止文件下载 G|IO~o0+  
public void siteStop() W[w8@OCNf  
{ ?5jkb  
bStop = true; l*b3Mg  
for(int i=0;i<nStartPos.length;i++) >$?$&+e}  
fileSplitterFetch.splitterStop(); qZCA16  
| u7vY/  
9q;+ Al^Z  
} r Fdq \BSi  
} 9m%[ y1v0  
//负责部分文件的抓取 "*XR'9~7  
**FileSplitterFetch.java OAR#* ~q  
*/ |jO&qT]{  
package NetFox; Rco#?'  
s?7g3H5#0k  
Abd&p N  
import java.io.*; !1w=_  
import java.net.*; P*)}ENY  
^)D[ W(*  
_l{G Hz  
public class FileSplitterFetch extends Thread { .E"hsGH9h  
shj S^CP  
Ef:.)!;jy  
String sURL; //File URL aXhgzI5]  
long nStartPos; //File Snippet Start Position x.xfMM2n  
long nEndPos; //File Snippet End Position ~X*)gS-=  
int nThreadID; //Thread's ID mp+ %@n.;  
boolean bDownOver = false; //Downing is over 4}gqtw:  
boolean bStop = false; //Stop identical q.g<gu]  
FileAccessI fileAccessI = null; //File Access interface o!gl :izb  
=K- B I  
m9a(f>C  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ca0~K42~  
{ ZlUd^6|:3  
this.sURL = sURL; A"2k,{d  
this.nStartPos = nStart; OB>Pk_eQK  
this.nEndPos = nEnd; gj0gs  
nThreadID = id; NYm2fFPc  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q1.w8$  
} y4w{8;Mh  
t+|c)"\5h  
.FtW $Y~y  
public void run() /RIvUC1  
{ cAC]%~orx  
while(nStartPos < nEndPos && !bStop) Z)~.OqRw]  
{ aP>%iRk'J!  
)lTkqz8v  
Z455g/=ye  
try{ $NWXn,Y'  
URL url = new URL(sURL); N3!x7J7A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2E9Cp  
httpConnection.setRequestProperty("User-Agent","NetFox"); qfd/t<?|D  
String sProperty = "bytes="+nStartPos+"-"; Cb%?s  
httpConnection.setRequestProperty("RANGE",sProperty); oe=^CeW"  
Utility.log(sProperty); PxhB=i!'$  
kXFgvIpg<  
1 `hj]@.]  
InputStream input = httpConnection.getInputStream(); /EZF5_`bT  
//logResponseHead(httpConnection); MN}@EQvW==  
&}_E~jKK  
4onRO!G,  
byte[] b = new byte[1024]; w4\b^iJz  
int nRead; f R$E*Jd  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /. k4Y  
{ d3v5^5kU  
nStartPos += fileAccessI.write(b,0,nRead); \tc 4DS  
//if(nThreadID == 1) C (L1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F.<sKQ&A  
} l{[{pAm  
R4.$9_ ui  
OlL FuVR  
Utility.log("Thread " + nThreadID + " is over!"); ,B_Nz}\8  
bDownOver = true; hX# y7m  
//nPos = fileAccessI.write (b,0,nRead); 66NJ&ac  
} U p=J&^.  
catch(Exception e){e.printStackTrace ();} bS=aFl#  
} ] lE6:^V  
} 0>} FNRC  
h:\WW;s[B  
}1 = V`N(  
//打印回应的头信息 v9QR,b` n  
public void logResponseHead(HttpURLConnection con) Q*u4q-DE  
{ %JF.m$-  
for(int i=1;;i++) !B5 }`*1D  
{ kTZ`RW&0  
String header=con.getHeaderFieldKey(i); ]a F,r"  
if(header!=null) +Wrj%}+  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,_ }  
Utility.log(header+" : "+con.getHeaderField(header)); 3)b[C&`  
else *p0n{F9  
break; K;^$n>Y  
} "#anL8  
} D/[(}o(  
Nj4=  
-'ePx f  
public void splitterStop() 9|R]Lz3PA  
{ yAz`n[  
bStop = true; z UN&L7D  
} 8,d<&3D  
^Tgu]t   
K:hZ  
} 5$9g4  
' P5t tI#|  
zg L0v5vk  
/* E:'TZ4Z  
**FileAccess.java /qM:;:N%j  
*//文件访问(定位,写) N.R,[K  
package NetFox; ?"-%>y@w  
import java.io.*; ElLDSo@WvR  
sx7;G^93  
x$ z9:'U  
public class FileAccessI implements Serializable{ !ZlBM{C  
Jm0o[4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .h O ) R.  
RandomAccessFile oSavedFile; /E8{:>2  
long nPos; Jse;@K5y  
CEbZj z|  
wtlIyE  
public FileAccessI() throws IOException ;n1< 1M>!  
{ >.'rN>B+  
this("",0); Ldqn<wNnI  
} j_YpkKh en  
a k&G=a6^  
vU= +  
public FileAccessI(String sName,long nPos) throws IOException O_-Lm4g?4  
{ ixc~DV+@[  
oSavedFile = new RandomAccessFile(sName,"rw"); G- nS0Kn:  
this.nPos = nPos; %A_h!3f&  
oSavedFile.seek(nPos); )lB 3U  
} Ne>yFl"u  
wyG7SA   
6_xPk`m  
public synchronized int write(byte[] b,int nStart,int nLen) JAEn 72  
{ Y.FqWJP=p  
int n = -1; n~`1KC4  
try{ zb<YYJ]  
oSavedFile.write(b,nStart,nLen); OAx5 LTd  
n = nLen; `?@7T-v  
} b/^i  
catch(IOException e) oZVq }}R  
{ nKxu8YAJe  
e.printStackTrace (); YK Cd:^u  
} :g@H=W  
, gYbi-E  
NHI(}Ea|]  
return n; Js{X33^Ju  
} y$-;6zk\]  
0_\@!#-sml  
?4QX;s7  
} m3Ma2jLWC  
DNYJR]>  
h zv4+1Wd[  
/* u Uy~$>V  
**SiteInfoBean.java ,dyCuH!B  
*/   %4  
package NetFox; {|:ro!&  
@ ={Hx$zL  
j_w"HiNBA  
public class SiteInfoBean { i6Zsn#Z7)  
cviPCjM  
OH+kN /Fd  
private String sSiteURL; //Site's URL v2ab  
private String sFilePath; //Saved File's Path Wycood*  
private String sFileName; //Saved File's Name Z@i"/~B|4\  
private int nSplitter; //Count of Splited Downloading File pGO=3=O  
qukym3F  
yv),>4_6  
public SiteInfoBean() M9*#8>  
{//nSplitter的缺省值为5 q-tm `t*7  
//default value of nSplitter is 5 Ng=_#<  
this("","","",5); : _,oD  
} TAd~#jB9  
<4{Jm8zJ  
uC2-T5n'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 108cf~2&  
{ 4xYW?s(  
sSiteURL= sURL; Dej_(Dz_S  
sFilePath = sPath; 0<^!<i(%  
sFileName = sName; Ad%3 fvn  
this.nSplitter = nSpiltter; V1h&{D\"  
o$4xinK  
(-e*xM m  
} SAQ|1I#"/  
 MjjN  
/);S?7u.  
public String getSSiteURL() SO!|wag$  
{ "bhF`,V  
return sSiteURL; B_ x?s  
} V DN@=/  
cM|!jnKm  
Tl/!Dn  
public void setSSiteURL(String value) ()\=(n!J  
{ 8gI f  
sSiteURL = value; &xgKHbg  
} r9\7I7z  
_`Lv@T.  
*PF}L%K(?  
public String getSFilePath() v-utDQT3  
{ D# Gf.c  
return sFilePath; iCZuE:I1K,  
} PKxI09B  
YU]|N 'mL2  
' 5F3,/r  
public void setSFilePath(String value) KFuP gp  
{ ^F="'/Pq[  
sFilePath = value; 9$~a&lXO5  
} AuW-XK.  
*hV$\CLT.  
_G62E $=  
public String getSFileName() 9| {t%F=-  
{ x 8_nLZ  
return sFileName; GxynLXWo>  
} V1]QuQ{&s  
Sy0-tK4  
X?B\+dq  
public void setSFileName(String value) ]iq2_{q  
{ 9!>Ks8'.d  
sFileName = value; \GP0FdpV  
} .{8?eze[m  
XusTU  
T=W;k<P\k  
public int getNSplitter() s` $YY_  
{ mzGMYi*  
return nSplitter; 0nu&JQ  
} HB0DG<c-  
Hl*V i3bQU  
-(Fhj Ir  
public void setNSplitter(int nCount) n@PXC8}  
{ f [DZ  
nSplitter = nCount; *u)#yEJ)  
} QNcbl8@  
} `z!6zo2d  
!8@8  
g)**)mz[  
/* ={k_ (8]  
**Utility.java ]*&`J4i  
*/ G)8H9EV  
package NetFox; ;4s7\9o  
ny'wS  
N2Q b+  
public class Utility { $ vt6~nfI  
h2_A'  
p`=v$_]?(  
public Utility() cGUsao  
{ i%3q*:A]2  
LUfo@R  
6-t:eo9  
} 9H%dK^C  
OBEHUJ5  
//线程睡眠 o @(.4+2m  
public static void sleep(int nSecond) 9lR-  
{ m+=L}[  
try{ =>Q$S  
Thread.sleep(nSecond); h{/lW#[  
} ur| vh5  
catch(Exception e) 2SRmh!hr  
{ l\"wdS}  
e.printStackTrace (); Xwz'h;Ks_  
} /1z3Q_M  
} r=cm(AHF  
9?Q0O\&uP  
//日志 E(miQ   
public static void log(String sMsg) #8CeTR23cw  
{ d]I3zS IC  
System.err.println(sMsg); i~i ?M)  
} _(J4  
n?S~(4%  
&j!q9F  
public static void log(int sMsg) Gg# 1k TK  
{ J_}Rsp ED  
System.err.println(sMsg); iVZ X  
} o! Y61S(  
} xWxgv;Ah  
Rl[SqmnI)@  
mBON>Z [4.  
/* J}Ji /  
**TestMethod.java R d|M)  
*/ G"|c_qX  
package NetFox; -40s  
9FcH\2J  
9w}_CCj3  
public class TestMethod { X(qs]:  
]\6*2E{1m  
/:+MUw7~  
public TestMethod() v%4zP%4Ak[  
{ ///xx/weblogic60b2_win.exe [n2)6B\/  
try{ 4Pkl()\c  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z11I1)%s  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :)j& t>aP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +BgUnu26  
fileFetch.start(); Lj Y@b  
} xW+ XN`77  
catch(Exception e){e.printStackTrace ();} }S=m: VKH  
@ev8"JZ1  
AVi,+n  
} Xp?WoC N  
m* rw?nLZ  
@M=\u-jJ.  
public static void main(String[] args) wak`Jte=}m  
{ q?=_{oH9  
new TestMethod(); Ox^VU2K;&.  
} _qU;`Q  
} ~ea&1+Z[3  
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