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http断点续传简单实现(java)

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/* >U vP/rp  
**SiteFileFetch.java x%l(0K  
*/ ? `p/jA  
package NetFox; H-PVV&r   
import java.io.*; -67Z!N  
import java.net.*; x ;|HT  
~;3yjO)l?)  
t,?, T~#9  
public class SiteFileFetch extends Thread { !fzS' pkk.  
=/Gd<qz3  
,*J@ic7"  
SiteInfoBean siteInfoBean = null; //文件信息Bean cuN9R G  
long[] nStartPos; //开始位置 f6%k;R.Wz  
long[] nEndPos; //结束位置 Hu"$ )V  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 XM`GK>*aC(  
long nFileLength; //文件长度 "[N2qJ}p  
boolean bFirst = true; //是否第一次取文件 `NN P<z+\  
boolean bStop = false; //停止标志 MY,~leP&  
File tmpFile; //文件下载的临时信息 6G2~'zqPc~  
DataOutputStream output; //输出到文件的输出流 L5bq\  
w7Yu} JY^  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) +]eG=. u  
public SiteFileFetch(SiteInfoBean bean) throws IOException $@L;j  
{ 0vqVE]C  
siteInfoBean = bean; ZAr6RRv ^  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); O>' }q/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); k24I1DlR8  
if(tmpFile.exists ()) KnkmGy  
{ LP"g(D2'n  
bFirst = false; 8\rca:cF   
read_nPos(); p< 7rF_?W0  
} \}$|Uo$O  
else .o/|]d`%  
{ I{89chi  
nStartPos = new long[bean.getNSplitter()]; }|Qh+{H*.  
nEndPos = new long[bean.getNSplitter()]; ,Vi_~b  
} 3gUY13C}:p  
ni/s/^  
6\.g,>   
L<!h3n  
} f6Y?),`  
&V?+Y2  
tg\Nm7I  
public void run() a fa\6]m  
{ sWlxt qg  
//获得文件长度 *|y'%y  
//分割文件 6]1RxrAV  
//实例FileSplitterFetch 6>WkisxG  
//启动FileSplitterFetch线程 ec!e  
//等待子线程返回 :zU4K=kR  
try{ #`_W?-%^  
if(bFirst) 2U[/"JL  
{ 8XH;<z<oJ  
nFileLength = getFileSize(); E <yQB39  
if(nFileLength == -1) 0kUhz\"R:q  
{ f/sz/KC]~  
System.err.println("File Length is not known!"); &MX&5@ Vu  
} +PYV-@q  
else if(nFileLength == -2) %bP+P(vZ  
{ aG7Lm2{c"  
System.err.println("File is not access!"); xQZOGq  
} vE[d& b[  
else %`$bQU  
{ 9BakxmAc  
for(int i=0;i<nStartPos.length;i++) \;-Yz  
{ YHN6/k7H  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \l=A2i7TQ  
} <IZr..|O  
for(int i=0;i<nEndPos.length-1;i++) 4M"'B A<  
{ &5HI   
nEndPos = nStartPos[i+1]; \ ERBb.  
} I]HYqI  
nEndPos[nEndPos.length-1] = nFileLength; ^X#)'\T  
} ~[!Tpq5  
} d*u3]&?x&f  
~Xx}:@Ld  
9vi+[3s/=;  
//启动子线程 `V/kM0A5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; # 9bw'm  
for(int i=0;i<nStartPos.length;i++) jXx~ 5  
{ MZ)lNU l  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fbI5!i#lz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VKPsg  
nStartPos,nEndPos,i); #: EhGlq8  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &x (D%+  
fileSplitterFetch.start(); Vb\^xdL>  
} l )r^|9{  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +v%+E{F$+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ([m4 dr  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &xr(Kb  
nEndPos = " + nFileLength); MNh:NFCRA  
// fileSplitterFetch[nPos.length-1].start(); .D7Gog3^<  
FS7D  
bz:En'2>F  
//等待子线程结束 %M_F/O  
//int count = 0; ?RE"<L  
//是否结束while循环 ^!m%:r7Dr  
boolean breakWhile = false; 7LaRFL.,kO  
nF-l4=  
9n5uO[D  
while(!bStop) s&%r?  
{ >d;U>P5.  
write_nPos(); mJ8EiRSE  
Utility.sleep(500); JrxQ.,*i  
breakWhile = true; C\[:{d  
g6gwNC:aF  
lNe5{'OrO  
for(int i=0;i<nStartPos.length;i++) $LBgBH &z  
{ Ct(^nn$A  
if(!fileSplitterFetch.bDownOver) -{oZK{a1  
{ 6d5q<C_3t  
breakWhile = false; OHY|< &*  
break; P e} T  
} MO1H?U hx  
} }L`Z<h*H  
if(breakWhile) tPk> hzW  
break; K=4|GZ~p}`  
)eX{a/Be  
ZP:+'\&J  
//count++; B_@p@6z  
//if(count>4) \+ Ese-la  
// siteStop(); `/G9*tIR8g  
} v/7^v}[<  
|@B|o-  
"-HWw?rx/  
System.err.println("文件下载结束!"); Cpn!}!Gnf  
} V\c`O  
catch(Exception e){e.printStackTrace ();}  l:a#B  
} l?X)]1  
do.XMdit  
%xX b5aY  
//获得文件长度 ;wHyX)&X $  
public long getFileSize() ##" Hui  
{ U @}r?!)"f  
int nFileLength = -1; I,/E.cRV<  
try{ }?CKE<#%  
URL url = new URL(siteInfoBean.getSSiteURL()); 7$Cv=8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ] < ;y_  
httpConnection.setRequestProperty("User-Agent","NetFox"); Co/04F.  
8qUNh#  
!Ks<%; rb  
int responseCode=httpConnection.getResponseCode(); 4`sW_ ks  
if(responseCode>=400) bz`rSp8h  
{ 2%-/}'G*  
processErrorCode(responseCode);  bIuOB|  
return -2; //-2 represent access is error k]c$SzJ>/  
} 9 H>J S  
R$2\Xl@qQF  
SO`b+B  
String sHeader; 0.~s>xXp  
rj29$d?Y9  
$%1oZ{&M  
for(int i=1;;i++) [KEw5-=i@  
{ a!&<jM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^_=bssaOd  
//Utility.log(in.readLine()); <Ug1g0.  
sHeader=httpConnection.getHeaderFieldKey(i); Om8Sgy?  
if(sHeader!=null) .sZ"|j9m  
{ m&- -$sr  
if(sHeader.equals("Content-Length")) ,C^u8Z|T  
{ |-]'~ @~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b~!Q3o'W  
break; =_$Hn>vO  
}  {T5u"U4  
} &8JK^zQq  
else ,/eAns`ZU  
break; DLoH.Fd  
} As|e=ut(  
} [n$6 T  
catch(IOException e){e.printStackTrace ();} nYTPcT4x|  
catch(Exception e){e.printStackTrace ();} ,UxAHCR~9  
.bNG:y>  
riSgb=7q9  
Utility.log(nFileLength); ' $"RQ=  
3oApazH*  
50Ov>(f@7  
return nFileLength; /kqa|=-`q  
} % 3<7HY]~  
m :2A[H+  
cJ'OqV F  
//保存下载信息(文件指针位置) 55zy]|F"  
private void write_nPos() -T>i5'2)  
{ +6(\7?  
try{ w u0q.]  
output = new DataOutputStream(new FileOutputStream(tmpFile)); eI/5foA  
output.writeInt(nStartPos.length); Z)<lPg!YAR  
for(int i=0;i<nStartPos.length;i++) G^le91$  
{ |}o3EX  
// output.writeLong(nPos); CWSc#E  
output.writeLong(fileSplitterFetch.nStartPos); -o@L"C>   
output.writeLong(fileSplitterFetch.nEndPos); #1p\\Av  
} C/q!!  
output.close(); {vp*m :K  
} 2~%^ y6lR  
catch(IOException e){e.printStackTrace ();} n]jw!;  
catch(Exception e){e.printStackTrace ();} nPUD6<bF  
} M[QQi2:&  
U.N?cKv  
|u+!CR  
//读取保存的下载信息(文件指针位置) ur[^/lxx0  
private void read_nPos() FzG>iC}  
{ <4582x,G  
try{ &W{v(@  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $t0JfDd6Ky  
int nCount = input.readInt(); . Gb!mG  
nStartPos = new long[nCount]; &mm!UJ  
nEndPos = new long[nCount]; U|x#'jGo'  
for(int i=0;i<nStartPos.length;i++) =X7_!vSv  
{ -L!lJ  
nStartPos = input.readLong(); 8k;il54#  
nEndPos = input.readLong(); k`J|]99Wb  
} \susLD  
input.close(); 7 4]qz,  
} } g%v<'K  
catch(IOException e){e.printStackTrace ();} i:1 @ vo  
catch(Exception e){e.printStackTrace ();} &_74h);2I:  
} KtHkLYOCG  
aP#/%  
;3o7>yEv  
private void processErrorCode(int nErrorCode) 1:J+`mzpl  
{ c7RQ7\  
System.err.println("Error Code : " + nErrorCode); n/S+0uT  
} !@ {sM6U  
< pZwM  
jwP5pu  
//停止文件下载 *D.Ajd.G  
public void siteStop() a4pewg'  
{ _PSOT5{  
bStop = true; L$,yEMCe  
for(int i=0;i<nStartPos.length;i++) lSc=c-iOv  
fileSplitterFetch.splitterStop(); kT:I.,N   
!;0K=~(Y^  
"F[7b!>R  
} D"%>  
} [2E(3`-u  
//负责部分文件的抓取 h}kJ,n  
**FileSplitterFetch.java Ih OAMH1  
*/ lc3Gu78 A/  
package NetFox; (>NZYPw^3  
Z B`d&!W>  
7VL|\^Y`q  
import java.io.*; ]sJC%/  
import java.net.*; dT[JVl+3=  
'u~0rMe4})  
;#:AM;  
public class FileSplitterFetch extends Thread { W1EYVXN  
O8 SE)R~  
{`,)<R>}  
String sURL; //File URL X-#&]^d  
long nStartPos; //File Snippet Start Position 5DVYHN9c|  
long nEndPos; //File Snippet End Position zTc*1(^  
int nThreadID; //Thread's ID 6q6xqr:W  
boolean bDownOver = false; //Downing is over "c|Rpzs[  
boolean bStop = false; //Stop identical z+-o}i  
FileAccessI fileAccessI = null; //File Access interface w ?*eBLJ(G  
e[s}tjx  
/(.:l +[w[  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9g>)7Ne  
{ 9\c]I0)3p  
this.sURL = sURL; AI`k }sA~  
this.nStartPos = nStart; ~?FhQd\Q  
this.nEndPos = nEnd; L9lJ4s  
nThreadID = id; Hf\sF(, (  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `G_~zt/  
}  6su~SPh  
1m#.f=u{R  
`j(._`8%a  
public void run() bwH[rT!n  
{ CH&{x7$he  
while(nStartPos < nEndPos && !bStop) *tgu@9b  
{ Jv+w{"&  
@XXPJq;J  
&K{8- t  
try{ n:P:im?,y*  
URL url = new URL(sURL); 9)NKI02M|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L!lmy&1  
httpConnection.setRequestProperty("User-Agent","NetFox"); N2"B\  
String sProperty = "bytes="+nStartPos+"-"; p@nj6N.--  
httpConnection.setRequestProperty("RANGE",sProperty); 6(rN(C  
Utility.log(sProperty); /s} "0/Y\  
<|jh3Hlp  
rM"27ud[`_  
InputStream input = httpConnection.getInputStream(); cw{TS  
//logResponseHead(httpConnection); q\]X1N  
 dC{dw^  
^9:`D@Z+  
byte[] b = new byte[1024]; ao"2kqa)r  
int nRead; #[bL9R5NC  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )38%E;T{X  
{ .Zv~a&GE  
nStartPos += fileAccessI.write(b,0,nRead); & UOxS W  
//if(nThreadID == 1) >Vjn]V5y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BEvY&3%l  
} "`V@?+3  
%,_ZVgh0  
XhHgXVVGG<  
Utility.log("Thread " + nThreadID + " is over!"); ekL;SN  
bDownOver = true; }!oEjcX'  
//nPos = fileAccessI.write (b,0,nRead); <D~hhGb  
} $3G^}A"  
catch(Exception e){e.printStackTrace ();} e ,/]]E/o  
} ld@+p  
} uC^)#Y\"  
i7XY3yhC  
3NLn}  
//打印回应的头信息 LhbdvJAk@  
public void logResponseHead(HttpURLConnection con) iX]OF.:   
{ mn?F;= qE  
for(int i=1;;i++)  pE)NSZ  
{ qBX_v5pvVA  
String header=con.getHeaderFieldKey(i); dX cbS<  
if(header!=null) )|xu5.F  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~ p? ArZb  
Utility.log(header+" : "+con.getHeaderField(header)); -&>V.hi7  
else ;+E]F8G9r  
break; W_ `]7RO8  
} {MUiK 5:  
} ,bl }@0A  
]O"f%   
0N$7(.  
public void splitterStop() /B@{w-N  
{ /=m AVA  
bStop = true; l5{60$g  
} i *.Y  
m7'<k1#"Y  
<J&S[`U!  
} MF4 (  
k56Qas+3=  
PlzM`g$A  
/* =#V^t$  
**FileAccess.java #y:D{%Wp  
*//文件访问(定位,写) (w hl1  
package NetFox; 1RYrUg"s"  
import java.io.*; ][$I~ nRf  
1P!)4W  
1l$Ei,9  
public class FileAccessI implements Serializable{ aZ4EcQ@-$]  
 p@ ^G)x  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RhE~-b[X  
RandomAccessFile oSavedFile; {=ox1+d  
long nPos; \"a{\E,{;  
4`5yrC d  
?uq`|1`  
public FileAccessI() throws IOException t>\sP   
{ UucI>E3?P{  
this("",0); :25LQf^nz  
} W "'6 M=*  
A `Z/B[)  
QhZg{v[d  
public FileAccessI(String sName,long nPos) throws IOException CQ!pt@|d  
{ 1hG#  
oSavedFile = new RandomAccessFile(sName,"rw"); t WI-  
this.nPos = nPos; l a3B`p  
oSavedFile.seek(nPos); P1-eDHYw  
}  arYq$~U  
 ? }M81  
;o9h|LRs  
public synchronized int write(byte[] b,int nStart,int nLen) @sXv5kZ:  
{ 8<6H2~5<  
int n = -1; ==dKC;  
try{ *LEy# N  
oSavedFile.write(b,nStart,nLen); e}UQN:1  
n = nLen; bF"l0 jS  
} HuevDy4  
catch(IOException e) u:l-qD9=(  
{ yix[zfQt0  
e.printStackTrace (); [;u#79aE  
} ]q]xU,  
;+9OzF ;  
IO\4dU)  
return n; gQn%RPMh  
} UkL1h7}a\  
%fj5 ;}E.  
@Vm*b@  
} n Nt28n@  
VXeO}>2S  
K zWo}tT  
/* yb`PMjj15  
**SiteInfoBean.java 5;a*Xf%V  
*/ .xRdKt!p  
package NetFox; zPby+BP  
r_T)| ||v  
[X(4( 1i  
public class SiteInfoBean { 6Tl6A>%s  
5n@YNaoIb  
XiW1X6  
private String sSiteURL; //Site's URL ;*(-8R/  
private String sFilePath; //Saved File's Path GK@OdurAR  
private String sFileName; //Saved File's Name vF72#BNs  
private int nSplitter; //Count of Splited Downloading File 'cD?0ou`o  
M+/G>U  
$V~@w.-Z#  
public SiteInfoBean() H"A%mrb  
{//nSplitter的缺省值为5  Gl~l  
//default value of nSplitter is 5 +?_!8N8  
this("","","",5); )^j_O^T5  
} '}.Yf_  
.biq)L e  
gaF6 j!p  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ATs_d_Sz  
{ /_C2O"h  
sSiteURL= sURL; GY~$<^AK  
sFilePath = sPath; \-\>JPO~<  
sFileName = sName; S=UuEmU5N  
this.nSplitter = nSpiltter; y'R}  
%8'8XDq^8  
dOhSqx56  
} RZa/la*  
'a~@q~!  
xT HD_?d  
public String getSSiteURL() .t8)`MU6.  
{ 2b"*~O;  
return sSiteURL; LF dvz0  
} ) c@gRb~  
GP} ;~  
!]4u"e  
public void setSSiteURL(String value) iU)I"#\l'k  
{ (,|,j(=]  
sSiteURL = value; Z\!,f.>g  
} UK=ELvt]  
S=@+qcI  
{:X'9NEE  
public String getSFilePath() ]J7qsMw  
{ i)i>Ulj*i  
return sFilePath; :qzg?\(  
} YI0 wr1N  
u64#,mC[*  
",#.?vT`  
public void setSFilePath(String value) -cgO]q+Oq  
{ k/K)nH@)  
sFilePath = value; \:vF FK4a  
} )%(ZFn}  
8v$q+Wic  
)G P;KUVae  
public String getSFileName() r%,?uim#  
{ %cF`x_h[j  
return sFileName; u0C:q`;z  
} wkg4I.  
N?\X 2J1  
8P n  
public void setSFileName(String value) ni;_Un~  
{ =EJ&=t  
sFileName = value; ~k*]Z8Z  
} (,Y[2_Zv  
 3.&BhLT  
ZrN(M p  
public int getNSplitter() Yh<F-WOo2  
{ Gek?+|m  
return nSplitter; G]lGoa}]`u  
} LuS@Kf8N+  
k+QGvgP[4@  
N[{rsUBd  
public void setNSplitter(int nCount) k!c7eP"%8^  
{ N/ a4Gl(  
nSplitter = nCount; >S5J^c  
} 6-U_TV  
} JVAyiNIH>M  
(5T>`7g8  
0R?1|YnB  
/* (UkP AE  
**Utility.java oO2DPcK  
*/ )5|9EXh  
package NetFox; 91R# /i  
**q8vhJM  
vC]X>P5Px  
public class Utility { M9"Bx/  
W;u.@I&  
(-C)A-Uo&  
public Utility() tU4#7b:Y  
{ {;$oC4  
C[FHqo9M?H  
d9{lj(2P  
} %. 1/ #{  
((M,6Q}  
//线程睡眠 yP"2.9\erH  
public static void sleep(int nSecond) E '6>3n  
{ `KQx#c>'  
try{ ;4 O[/;i  
Thread.sleep(nSecond); LnR>!0:c  
} 8xy8/UBIk0  
catch(Exception e) =2!p>>t,d;  
{ -2hirA<^  
e.printStackTrace (); #|9W9\f,  
} :8 2T!  
} &8IBf8  
CW1l;uwtU  
//日志 7Kw'Y8  
public static void log(String sMsg) l b(  
{ CCTU-Xz/  
System.err.println(sMsg); '_v~+  
} e-dkvPr  
BA\aVhmx  
}geb959  
public static void log(int sMsg) YZ~MByu  
{ \[9VeqMU  
System.err.println(sMsg); H-_gd.VD  
} "7cty\  
} ~[CFs'`(2  
j\C6k  
e!VtDJDS  
/* xpdpD  
**TestMethod.java TgkVd]4%  
*/ Nh\vWAz9  
package NetFox; =j>xu|q  
9E7G%-  
,X!6|l8  
public class TestMethod { '#6e Ub  
&nEL}GM)E  
;!<}oZp{  
public TestMethod() 4*EMd!E=<  
{ ///xx/weblogic60b2_win.exe b 3x|Dq.  
try{ 0B.Gt&O al  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vF^d40gV  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~qinCIj  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wR%Ta-  
fileFetch.start(); UA<Fxt  
} z0[@O)Sj  
catch(Exception e){e.printStackTrace ();} ;UQza ]i  
!q\8`ss  
5` ^@k<  
} P&0eu  
wI@87&  
P j   
public static void main(String[] args) "3RFy i  
{ !!C/($  
new TestMethod(); I=dG(?#7%  
} R XCn;nM4  
}  [ <X%  
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