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http断点续传简单实现(java)

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/* [g&Q_+,j  
**SiteFileFetch.java cU%#oEMf<  
*/ :ozHuHJ#  
package NetFox; D~NH 4B  
import java.io.*; dfc-#I p?  
import java.net.*; f`/JY!u j{  
;P5\EJo  
[rqq*_eB  
public class SiteFileFetch extends Thread { lQi2ym?  
-("79v>#  
Pa0tf:  
SiteInfoBean siteInfoBean = null; //文件信息Bean jY87N Hg  
long[] nStartPos; //开始位置 1ww|km  
long[] nEndPos; //结束位置 ;Qk*h'}f  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Rp}6}4=d  
long nFileLength; //文件长度 d cPh @3  
boolean bFirst = true; //是否第一次取文件 @_1$ <8  
boolean bStop = false; //停止标志 V)!Oss;i  
File tmpFile; //文件下载的临时信息 =J0FT2 d  
DataOutputStream output; //输出到文件的输出流 D rHMlk5  
LeQ2,/7l:  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) !*C^gIQGU  
public SiteFileFetch(SiteInfoBean bean) throws IOException Qi6vP&  
{ Zm&Zz^s  
siteInfoBean = bean; 8{%/!ylJz  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); N7+K$)3  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0)k%nIhj  
if(tmpFile.exists ()) mQ VduG  
{ 1m}'Y@I  
bFirst = false; rZ:  
read_nPos(); ?kE2 S6j5  
} W 86S)+h  
else 'qQ DM_+  
{ !Aunwq^  
nStartPos = new long[bean.getNSplitter()]; }-: d*YtK  
nEndPos = new long[bean.getNSplitter()]; \m5:~,p=  
} <C# s0UX  
1PLKcU  
~z32%k  
jqb,^T|j;m  
} Zu&trxnNf[  
xhg{!w  
.7~Kfm@2  
public void run() U:_T9!fG  
{ :T%,.sH  
//获得文件长度 n9cWvy&f  
//分割文件 -}4H'%Z(i  
//实例FileSplitterFetch $dorE ~T  
//启动FileSplitterFetch线程 +-qD!(&-6  
//等待子线程返回 '~3( s?B  
try{ cX *  
if(bFirst)  78qf  
{ LP=!u~?  
nFileLength = getFileSize(); =E4nNL?  
if(nFileLength == -1) 5jx{O${u  
{ OK3B6T5w=  
System.err.println("File Length is not known!"); wT*`Od8w  
} K# _plpr  
else if(nFileLength == -2) C[gSiL  
{ YJ rK oK}  
System.err.println("File is not access!"); 8'`&f &  
} HAGWA2wQ  
else b cz<t)  
{ O!Mm~@MoA  
for(int i=0;i<nStartPos.length;i++) xv4nYm9  
{ z)QyQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); )TRDM[u  
} }Z0)FU +  
for(int i=0;i<nEndPos.length-1;i++) e<iTU?eJM  
{ q.Z0Q  
nEndPos = nStartPos[i+1]; }@ 1LFZx  
} GbB&kE3KP  
nEndPos[nEndPos.length-1] = nFileLength; 6kIq6rWF9  
} eUF PzioW  
} IQ2<Pinv  
ELY$ ]^T  
2z )h,<D  
//启动子线程 ,Z MYCl]  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yU .B(|  
for(int i=0;i<nStartPos.length;i++) szmjp{g0  
{ #cjB <APY  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^9cqT2:t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {Z-5  
nStartPos,nEndPos,i); JhB{aW>  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M&Ycw XV:Z  
fileSplitterFetch.start(); q'  _  
} :V+t|@m5l  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `pII-dSC%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ':.d,x)  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qDcl;{L  
nEndPos = " + nFileLength); *2;w;(-s  
// fileSplitterFetch[nPos.length-1].start(); ]S;e#u{QE  
MzJ5_}  
"uZ'oN  
//等待子线程结束 8&dmH&  
//int count = 0; "* 'rzd  
//是否结束while循环 w5qhKu!1  
boolean breakWhile = false; v[ F_r  
ukG1<j7.  
1AoBsEnd  
while(!bStop) dQ;rO$c o  
{ M}38uxP  
write_nPos(); ^@{'! N  
Utility.sleep(500); DrMcE31  
breakWhile = true; w :^b3@gd  
[DjdR_9*I  
}o)GBWqHR  
for(int i=0;i<nStartPos.length;i++) (qohb0  
{ ,:=E+sS  
if(!fileSplitterFetch.bDownOver) "#[Y[t\Ia  
{ x`C;  
breakWhile = false; k`\DC\0RG  
break; nwO;>Qr  
} ckhW?T>l  
} tk1qgjE(?  
if(breakWhile) {wA@5+[  
break; BT`/O D@  
< >f12pu  
{yspNyOx  
//count++; /\#qz.c2K  
//if(count>4) N;Hf7K  
// siteStop(); %v}:#_va]  
} .HGEddcC  
8V~w3ssz  
XPWK"t0 1  
System.err.println("文件下载结束!"); mYa0_P%^  
} ~^Vt)/}Q  
catch(Exception e){e.printStackTrace ();} HnOp*FP  
} ''f  
A:NsDEt  
7cvbYP\<lv  
//获得文件长度 hnE@+(d=qJ  
public long getFileSize()  $7|0{Dw  
{ B;G|2um:$  
int nFileLength = -1; {#Gr=iv~N  
try{ `[o^w(l:5@  
URL url = new URL(siteInfoBean.getSSiteURL()); 8a-[Q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S~Nx;sB  
httpConnection.setRequestProperty("User-Agent","NetFox"); C7qbofoV  
of{wZU\J+9  
L & PhABZ  
int responseCode=httpConnection.getResponseCode(); LuQ=i`eXx  
if(responseCode>=400) u!{P{C  
{ nM}X1^PiK"  
processErrorCode(responseCode); '1.T-.4>&  
return -2; //-2 represent access is error {u9VHAXCf  
} 6Y}#vZ  
2psLX  
,F:l?dfB\I  
String sHeader; qx`*]lX  
,Sz*]X  
"d.qmM  
for(int i=1;;i++) ! daXF&q  
{ oSy[/Y44a  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +-8uIqZ  
//Utility.log(in.readLine()); CE*@CkC0z  
sHeader=httpConnection.getHeaderFieldKey(i); ;t*45  
if(sHeader!=null) xj%h-@o6  
{ b.ow0WYe  
if(sHeader.equals("Content-Length")) (A(d]l  
{  D&N5)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t3U*rr|A  
break; nC[L"%E|se  
} npbNUKdz  
} na8A}\!<  
else skZxR5v3~L  
break; WnHf)(J`"  
} \[Rh\v&  
} cB?HMLbG>  
catch(IOException e){e.printStackTrace ();}  >cSc   
catch(Exception e){e.printStackTrace ();} *K m%Vl  
{\lu; b!  
rxm!'.+  
Utility.log(nFileLength); vco:6Ab$  
X$%RJ3t e  
ZH~m%sA  
return nFileLength; M@{GT/`Pf  
} X "1q$xwc  
}$iH 3#E8  
n*bbmG1  
//保存下载信息(文件指针位置) KvktC|~?  
private void write_nPos() hQl3F6-ud  
{ 46}/C5  
try{ PtmdUHvD  
output = new DataOutputStream(new FileOutputStream(tmpFile)); BnAia3z  
output.writeInt(nStartPos.length); Eiz\Nb  
for(int i=0;i<nStartPos.length;i++) LFg<j1Gk`  
{ Pme`UcE3H  
// output.writeLong(nPos); 3go!P])  
output.writeLong(fileSplitterFetch.nStartPos); rq2XFSXn  
output.writeLong(fileSplitterFetch.nEndPos); o.Q |%&1  
} =_L"x~0I-  
output.close(); 1Qf5H!5vx  
} [ &R-YQ@  
catch(IOException e){e.printStackTrace ();} t{84ioJ"$  
catch(Exception e){e.printStackTrace ();} 0)9GkHVu(  
} uX`Jc:1q3  
Cw Z{&  
yUEUIPL  
//读取保存的下载信息(文件指针位置) !|Vjv}UO  
private void read_nPos() u%h]k ,(E  
{ |h6)p;`gc  
try{ : <m0 GG  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u5T \_0  
int nCount = input.readInt(); %2/WyD$U  
nStartPos = new long[nCount]; D~2,0K  
nEndPos = new long[nCount]; #lV&U  
for(int i=0;i<nStartPos.length;i++) m,)Re8W-  
{ 97$y,a{6  
nStartPos = input.readLong(); ScM2_k`D  
nEndPos = input.readLong(); F"a,[i,[W  
} I uhyBo  
input.close(); ) `;?%N\  
} M# S:'WN  
catch(IOException e){e.printStackTrace ();} "$ u"Py  
catch(Exception e){e.printStackTrace ();} +J.^JXyp0  
} 5l{_E:.1  
I>ofSaN  
8kO|t!?:U  
private void processErrorCode(int nErrorCode) a)`h*P5@  
{ .Jou09+  
System.err.println("Error Code : " + nErrorCode); |$6Gp Aq!  
} uQpV1o5iA  
_Se>X=  
Xo]FOJ 5  
//停止文件下载 d{9jd{ _#G  
public void siteStop() 7J0 PO}N  
{ (K0FWTmm  
bStop = true; KOw Ew~  
for(int i=0;i<nStartPos.length;i++) ,uDB ]  
fileSplitterFetch.splitterStop(); :vV?Yv%P)n  
bpKb<c  
?WUu@Z  
} #(XP=PUj  
} iCz,|;w%  
//负责部分文件的抓取 =o+t_.)N  
**FileSplitterFetch.java Lqwc:%Y:_  
*/ g($y4~#  
package NetFox; Qv']*C[!z  
nA%-<  
-+O8v;aC'  
import java.io.*; k('2K2P  
import java.net.*; &b{L|I'KYT  
.,tf[w 71  
Lo9+#ITyx  
public class FileSplitterFetch extends Thread { ^Z\1z!{R  
kdg Q -UN$  
3#5sj >  
String sURL; //File URL =Z%&jul  
long nStartPos; //File Snippet Start Position K<\TF+  
long nEndPos; //File Snippet End Position >f}rM20Vm  
int nThreadID; //Thread's ID b"{7f   
boolean bDownOver = false; //Downing is over Uv5E$Y"e10  
boolean bStop = false; //Stop identical !U=;e?o  
FileAccessI fileAccessI = null; //File Access interface y{"8VT)  
L88oh&M  
8G(wYlxi  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;~xkT'  
{ /XnI>  
this.sURL = sURL; &hqGGfVsd  
this.nStartPos = nStart; U .G*C  
this.nEndPos = nEnd; 5RZAs63t  
nThreadID = id; <R_3; 5J%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %o*afd  
} >W 8!YOc  
.X YSO  
[+ 1([#  
public void run() )mp0k%  
{ VYlg+MlT0  
while(nStartPos < nEndPos && !bStop) =C5 [75z#+  
{ h:j-Xd$H+  
nD E5A  
H^'EY:|  
try{ .>h|e_E  
URL url = new URL(sURL); VZw("a*TB  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >;0z-;k6  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4[rD|  
String sProperty = "bytes="+nStartPos+"-"; !"p,9  
httpConnection.setRequestProperty("RANGE",sProperty); !4-NbtT  
Utility.log(sProperty); Z`< +8e  
]3Mm"7`  
F~<$E*&h@  
InputStream input = httpConnection.getInputStream(); e|]g ?!  
//logResponseHead(httpConnection); ezHj?@  
N b(se*Y#  
B/pNM81(  
byte[] b = new byte[1024]; cUS2* 7h  
int nRead; `(Ei-$ >U&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6n;ewl}  
{ N[zI@>x  
nStartPos += fileAccessI.write(b,0,nRead); 42Ql^ka  
//if(nThreadID == 1) $mp7IZE|  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lf7iOW9U3  
} */?L_\7  
x{RTI#a.  
$"x(:  
Utility.log("Thread " + nThreadID + " is over!"); dp_J*8  
bDownOver = true; oLBpG1Va  
//nPos = fileAccessI.write (b,0,nRead); WMl_$Fd6  
} .DCp)&m l;  
catch(Exception e){e.printStackTrace ();} }RW4  
} BOfO$J}  
} YHCXVu<.b  
\h _hd%'G  
${e(#bvGZ  
//打印回应的头信息 tHhY1[A8m  
public void logResponseHead(HttpURLConnection con) 6S ]GSS<  
{ [yjC@docH  
for(int i=1;;i++) iY.~N#Q  
{ `M"b L|[R  
String header=con.getHeaderFieldKey(i); "eGS~-DVK  
if(header!=null) p7 2+:I  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E/AM<eN  
Utility.log(header+" : "+con.getHeaderField(header)); }{E//o:Ta  
else [xM07%:  
break; SLZv`  
} ~+^,o_hT  
} p|Z"< I7p(  
/"Rh bE   
KasOh"W.P  
public void splitterStop() +Y 3_)  
{ 0-FwHDxw  
bStop = true; 7B+?1E(  
} h :NHReMT  
A+ Z3b:}~  
$W` &7  
} :GGsQ n  
D {>, 2hC  
0Wv9K~F  
/* Tz%l 9aC  
**FileAccess.java ,3N8  
*//文件访问(定位,写) j>0S3P,  
package NetFox; /A##Yv!biR  
import java.io.*; 8>O'_6Joj  
Rp.@  
;|9VPv/  
public class FileAccessI implements Serializable{ AGrGZ7p]  
F fl`;M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 => -b?F0(c  
RandomAccessFile oSavedFile; Zj`eR\7~  
long nPos; TX;OA"3=\-  
%'^m6^g;  
.8.ivfmJh  
public FileAccessI() throws IOException ) @))3  
{ ?86h:9  
this("",0); Bg7?1m  
} <J`_Qc8C  
{"4t`dM  
@/|sOF;8W  
public FileAccessI(String sName,long nPos) throws IOException swlxV@NQ  
{ ^_2Ki   
oSavedFile = new RandomAccessFile(sName,"rw"); NW!e@;E+i  
this.nPos = nPos; Km\M /j|  
oSavedFile.seek(nPos); Uc7X)  
} x1A^QIuxO  
AO^F6Y/  
Y^3tk}yru  
public synchronized int write(byte[] b,int nStart,int nLen) X3 a:*1N  
{ b/ZX}<s(1=  
int n = -1; :(I)+;M}P  
try{ !?Ow"i-lp  
oSavedFile.write(b,nStart,nLen); _k6N(c2Nd  
n = nLen; 4 Ag+  
} U.>n]/&  
catch(IOException e) ,9W0fm \t  
{ vi lNl|  
e.printStackTrace (); ,wZ[Y 3  
} xB9^DURr\  
R<JI  
Hi.JL  
return n; >@]E1Qfe  
} ;'p0"\SV  
73N%_8DH  
a.w,@!7  
} 1d-j_ H`s  
%NxNZe  
<NS= <'U  
/* xbn+9b  
**SiteInfoBean.java 4b7}Sr=`  
*/ S0p]:r ";x  
package NetFox; E 8,53$  
EHo"y.ODg  
Qj3UO]>  
public class SiteInfoBean { 17};I7  
G_dia6  
*OsXjL`f  
private String sSiteURL; //Site's URL O#u)~C?)8  
private String sFilePath; //Saved File's Path ~ RTjcE  
private String sFileName; //Saved File's Name @h ^5*M  
private int nSplitter; //Count of Splited Downloading File gdkO|x  
p4aM`PW8>=  
5!y3=.j  
public SiteInfoBean() W>1\f0'  
{//nSplitter的缺省值为5 rEddX  
//default value of nSplitter is 5 S93NsrBbY  
this("","","",5); C"0gAN  
} bS0^AVA  
QouTMS-b  
/B}]{bcp$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Fb-NG.Z#  
{ LM*9b  
sSiteURL= sURL; CR, Y%0vQ  
sFilePath = sPath; a?+) K  
sFileName = sName; RsrZ1dhPvV  
this.nSplitter = nSpiltter; ?%;uR#4  
3zh'5qQ  
kTFN.kQx@  
} 1 u&P,&T  
C,fIwqOr3  
M_*w)<  
public String getSSiteURL() e@ F& /c  
{ g:f0K2)\r:  
return sSiteURL; q:?g?v  
} 0imz }Z]  
uy`U1>  
'# (lq5 c  
public void setSSiteURL(String value) ?$r+#'asd(  
{ 3&2,[G04  
sSiteURL = value; U?>zq!C&R  
} V(w[`^I>~  
^P{'l^CVX  
*23  
public String getSFilePath() ,pAMQ5  
{ *wh'4i}u  
return sFilePath; aD 3$z;E  
} ;7 IVg[f  
Y-9]J(  
1J<-P9 vk+  
public void setSFilePath(String value) :ye)%UU"|:  
{ IM +Dm  
sFilePath = value; VN$#y4  
} @br%:Nt  
L^ +0K}eD  
75^-93  
public String getSFileName() jh g!K.A  
{ A;Zg:  
return sFileName; JaIj 9KLNX  
} }i/{8Ou W  
0Fi7|  
?BWWb   
public void setSFileName(String value) 3QXGbu}:h!  
{ KTf!Pf?g  
sFileName = value; 2etlR  
} T /] ayc:  
'{7A1yJnY%  
kg !@i7  
public int getNSplitter() +<3tv&"  
{ ]B5\S  
return nSplitter; O+'Pq,hn  
} @aj"1 2  
5_`.9@eh.  
/&kTVuN"(  
public void setNSplitter(int nCount) ,'ndQ{\9  
{ XeZv%` ?  
nSplitter = nCount; ?G8 D6  
} kdoE)C   
} wvUph[j}J  
("{AY?{{  
$s) ^zm~  
/* j"YJ1R-5  
**Utility.java Q |l93Rb`  
*/ lGcHfW)Y  
package NetFox; 67n1s  
x#ouR+<  
Ebq5P$  
public class Utility { ]-ZD;kOr  
y:W$~<E`p  
g`1*p|  
public Utility() `NGCUGQ_7  
{ 4!monaB"e  
6 #QS 5  
1F$a My?  
} YemOP9  
{8UBxFIM(  
//线程睡眠 ^U`[P@T  
public static void sleep(int nSecond) 0<^K0>lm p  
{ Kh5:+n_X  
try{ K zM\+yC  
Thread.sleep(nSecond); aV>w($tdd  
} xDVzHgbf  
catch(Exception e) - 6  
{ @A yC0}  
e.printStackTrace (); mFo6f\DHr`  
} Z NuyGo;  
} Y RA[qc  
dXdU4YJ X  
//日志 sN;U,{  
public static void log(String sMsg) yJKezIL\z  
{  w[VWk  
System.err.println(sMsg); sA` bPhk  
} N>gv!z[E  
Ii4 Byyfx  
HD`Gi0  
public static void log(int sMsg) R)<>} y  
{ 3J [P(G>Q  
System.err.println(sMsg); ;w@:  
} ~ xXB !K~C  
} >j$f$*x  
s2d;601*b  
9@:&E  
/* uQ&xoDCB  
**TestMethod.java -gC=%0sp\  
*/ .JH3,L"S^  
package NetFox; !>2s5^JI9  
-R:1-0I$  
 [bv.`  
public class TestMethod { xeu] X|,  
n#x{~oQc  
3[8'pQ!&  
public TestMethod() <xc"y|7X  
{ ///xx/weblogic60b2_win.exe q WP1i7]=/  
try{ Y$'fds4P  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sG^b_3o)A  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :v&GA s6H  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _ b#9^2o  
fileFetch.start(); FiIN \  
} !H.&"~w@  
catch(Exception e){e.printStackTrace ();} u}u2{pO!  
3K54:  
9{>m04888  
} Nf$Y-v?i  
Q <78< #I  
8LiRZ"  
public static void main(String[] args) OP<@Xz  
{ wRLkO/Fw  
new TestMethod(); Kj'm<]u  
} GR|Vwxs<@P  
} &<v# ^2S3  
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