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http断点续传简单实现(java)

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/* v-@@>?W-  
**SiteFileFetch.java -JkO[ IF  
*/ 0}!lN{m?  
package NetFox; ^hJ ,1{o  
import java.io.*; efm<bJB2  
import java.net.*; 0cVXUTJ|W  
K>~l6  
S6I8zk)Z4  
public class SiteFileFetch extends Thread { >^}z  
~{{:-XkVB  
qlP=Y .H  
SiteInfoBean siteInfoBean = null; //文件信息Bean s:{%1/  
long[] nStartPos; //开始位置 *a4eL [  
long[] nEndPos; //结束位置 U^I'X7`r  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 C7:Ry)8'I  
long nFileLength; //文件长度 0>Nq$/!  
boolean bFirst = true; //是否第一次取文件 iddT.   
boolean bStop = false; //停止标志 $cedO']  
File tmpFile; //文件下载的临时信息 v'=APl+_  
DataOutputStream output; //输出到文件的输出流 )i>KgX  
BGS6uV4^>  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 64cmv}d_  
public SiteFileFetch(SiteInfoBean bean) throws IOException ;2~Q97c0  
{ ;DpK* A  
siteInfoBean = bean; x~.U,,1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Zl*!pQ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 1-fz564  
if(tmpFile.exists ()) Zx{'S3W  
{ _BV:i:z  
bFirst = false; s.R(3}/  
read_nPos(); dE~ns ,+  
} wH.'EC  
else 3& $E  
{ ZVL0S{V-mh  
nStartPos = new long[bean.getNSplitter()]; "-oC,;yq  
nEndPos = new long[bean.getNSplitter()]; 6fiJ' j@  
} cE[lB08  
6=k^gH[g  
OWzIea@  
82<!b]^1  
} pY@+.V`a  
hb{(r@[WHv  
bB["Qd}Q  
public void run() |9h[Q[m  
{ ~Q0}>m,S  
//获得文件长度 Yv)/DsSyL  
//分割文件 Et (prmH  
//实例FileSplitterFetch ,??|R` S  
//启动FileSplitterFetch线程 p%_TbH3j`  
//等待子线程返回 AKVmUS;70  
try{ SF7Kb`>Y  
if(bFirst) 622).N4  
{ @{G(.S  
nFileLength = getFileSize(); l;ugrAo?  
if(nFileLength == -1) !ibp/:x  
{ e;$s{CNo  
System.err.println("File Length is not known!"); xnTky1zq  
} N Jf''e3  
else if(nFileLength == -2) 7pNh|#Uv'  
{ h7{W-AtM7_  
System.err.println("File is not access!"); n9%rjS$  
} -Y6JU  
else ,yoT3_%P  
{ 1,E/So   
for(int i=0;i<nStartPos.length;i++) x8^Dhpr6  
{ 9bB~r[k  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &}oDSD H^,  
} sgX~4W"J  
for(int i=0;i<nEndPos.length-1;i++) K(?7E6\vO  
{ TL5bX+  
nEndPos = nStartPos[i+1]; #{(rOb6H)  
} 711 z-  
nEndPos[nEndPos.length-1] = nFileLength; Ni`qU(I'|  
} 1/ HofiIa  
} JQb]mU%?  
udB}`<Q  
VC@o]t5  
//启动子线程 eP)RP6ON{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "](~VF[J8  
for(int i=0;i<nStartPos.length;i++) XxGm,A+>Ty  
{ bFpwq#PDW>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rr*IIG&.5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E4{8 $:q=  
nStartPos,nEndPos,i); \,WPFV  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GM5::M]fS  
fileSplitterFetch.start(); mxIEg?r(  
} m{g{"=}YR  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yC -4wn*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C-M op,w  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xc!"?&\*  
nEndPos = " + nFileLength); T M+7>a$  
// fileSplitterFetch[nPos.length-1].start(); 8L#sg^1V  
D`ZYF)[}J  
r`=d4dK-  
//等待子线程结束 mVxS[Gq  
//int count = 0; )9*WmFc+#  
//是否结束while循环 *]LM2J  
boolean breakWhile = false; NH{0KZ R  
30<^0J.1  
bV"0}|A~K  
while(!bStop) :KQ<rLd  
{ uwbj`lpf  
write_nPos(); 7"gy\_M  
Utility.sleep(500); t((0]j^  
breakWhile = true; vm(% u!_P  
X/Ae-1!  
:G!Kaa,r  
for(int i=0;i<nStartPos.length;i++) lHx$F ?  
{ ]'"$qm:  
if(!fileSplitterFetch.bDownOver) }&=C*5JN  
{ fE(rDQI  
breakWhile = false; ,QK>e;:Be  
break; q|~9%Pujg  
} N-^\e)ln  
} qZ4DO*%b3  
if(breakWhile) H)5]K9D  
break; )T^hyi$  
`8L7pbS%,Q  
O@l`D`  
//count++; Z@1rs#  
//if(count>4) 3+)i23[4=\  
// siteStop();  z=!xN5  
} >Zr`9$i  
?g!)[p`v  
q|S }5  
System.err.println("文件下载结束!"); =4?m>v,re  
} J<'4(}^|  
catch(Exception e){e.printStackTrace ();} [g<JP~4]  
} /vBpRm  
HxkhlNB  
sp JB6n(  
//获得文件长度 ;lP)  
public long getFileSize() 1:8ZS  
{ "]sr4Jg=  
int nFileLength = -1; IkD\YPL;  
try{ .7oz  
URL url = new URL(siteInfoBean.getSSiteURL()); [ z?<'Tj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o0AREZ+I  
httpConnection.setRequestProperty("User-Agent","NetFox"); r t f}4.  
291v R]  
<jxTI%'f59  
int responseCode=httpConnection.getResponseCode(); Up8#Nz T  
if(responseCode>=400) NKRNEq!  
{ 5{{u #W%=  
processErrorCode(responseCode); %KqXtc`O  
return -2; //-2 represent access is error `*WR[c  
} GR/ p%Y(  
4-s Uy  
t; "o,T  
String sHeader; 'l2`05   
9Czc$fSSt  
s I#K01;"  
for(int i=1;;i++) cBU>/ zIp  
{ F$d`Umqs;P  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /']Gnt G.  
//Utility.log(in.readLine()); ?L'ijzP  
sHeader=httpConnection.getHeaderFieldKey(i); 2nk}'HBe  
if(sHeader!=null) 0nBAO  
{ zg[ksny  
if(sHeader.equals("Content-Length")) d]CRvzW  
{ p VLfZ?78  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )wmXicURC  
break; X mLHZ,/  
} )abo5   
} f.Jz]WXw,  
else wF}/7b54  
break; y;uk|#qnPS  
} w_6h $"^x  
} !YCYmxw#  
catch(IOException e){e.printStackTrace ();} L[D}pL=  
catch(Exception e){e.printStackTrace ();} !x[ +rf  
D/rKqPp|!  
{um~]  
Utility.log(nFileLength); hmQD-E{Ab  
dKhDO`.s  
Y!}BmRLh2  
return nFileLength; {R\"x|  
} aabnlOVw  
c/b} 39X  
BJ1txdxvS  
//保存下载信息(文件指针位置) ^,@Rd\q  
private void write_nPos() AS~O*(po  
{ 4k}u`8 a  
try{ S&FMFXF@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `O-$qT, _  
output.writeInt(nStartPos.length); @32JMS<  
for(int i=0;i<nStartPos.length;i++) yPKeatH]  
{ g?)9zJ9  
// output.writeLong(nPos); S'lZ'H/  
output.writeLong(fileSplitterFetch.nStartPos); YEQ}<\B\&  
output.writeLong(fileSplitterFetch.nEndPos); [ q22?kT  
} y1B3F5  
output.close(); J1hc :I<;  
} *o`bBdZ  
catch(IOException e){e.printStackTrace ();} LsoP >vJG  
catch(Exception e){e.printStackTrace ();} u<:R Sg  
} "4zTP!Ow  
}"E?#&^  
!Hxx6/  
//读取保存的下载信息(文件指针位置) t /1KKEZM  
private void read_nPos() }hhDJ_I5M  
{ :voQ#f=  
try{ :k#Y|(  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }qRYXjS  
int nCount = input.readInt(); uv eTx  
nStartPos = new long[nCount]; YOy/'Le^:  
nEndPos = new long[nCount]; vaW, O/F  
for(int i=0;i<nStartPos.length;i++) {a\m0Bw/  
{ "xi)GH]H_  
nStartPos = input.readLong(); KYZ/b8C  
nEndPos = input.readLong(); ]W]o6uo7  
} NN>,dd3T  
input.close(); twq!@C  
} glm29hF  
catch(IOException e){e.printStackTrace ();} %[l5){:05  
catch(Exception e){e.printStackTrace ();} b[%sKl  
} =LC:1zn4  
q",n:=PL  
lo5,E(7~h  
private void processErrorCode(int nErrorCode) $~75/  
{ 'D;v>r  
System.err.println("Error Code : " + nErrorCode); :dc>\kUIv  
} #"|</*% >  
<}&n}|!  
IXDj;~GF  
//停止文件下载 AQw1,tGV  
public void siteStop() (Z fY/  
{ }.>( [\ q  
bStop = true; @2nar<  
for(int i=0;i<nStartPos.length;i++) g ]e^;  
fileSplitterFetch.splitterStop(); YKlYo~fGN9  
]6bh#N;.  
+mIO*UQi  
} v[E*K@6f  
} m0DD|7}+  
//负责部分文件的抓取 KmG*`Es  
**FileSplitterFetch.java W1dpKv  
*/ ycz6-kEp  
package NetFox; )"`(+Ku&c  
Dp3&@M"^yY  
<lopk('7  
import java.io.*; P-o/ax  
import java.net.*; U-&dn%Sq  
|3<tDq@+  
W< _9*{|E;  
public class FileSplitterFetch extends Thread { W$>srdG0$  
aAhXHsZ|26  
t6(LO9Qc  
String sURL; //File URL [H<![Z1*r  
long nStartPos; //File Snippet Start Position OGpy\0%  
long nEndPos; //File Snippet End Position ">_<L.,I  
int nThreadID; //Thread's ID % P .(L  
boolean bDownOver = false; //Downing is over K%h9'}pq>1  
boolean bStop = false; //Stop identical SaceIV%(  
FileAccessI fileAccessI = null; //File Access interface V3r1|{Z(  
lI~T>Lel2  
ZfsM($|a  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7}>Zq`]~  
{ j} t"M|`  
this.sURL = sURL; _IYd^c  
this.nStartPos = nStart; T#KF@8'-  
this.nEndPos = nEnd;  `S$zwot  
nThreadID = id; W6%\Zwav?)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #; ~`+[y?\  
} ?-C=_eZJ  
g?&_5)&  
1?%Q"*Y&  
public void run() s&&8~ )H  
{ 5-qk"@E W  
while(nStartPos < nEndPos && !bStop) v<CZ.-r\j  
{ &B ?TX.  
3>asl54  
O =m_P}K  
try{ 7~&  
URL url = new URL(sURL); Qf|x]x*5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !8YZ;l  
httpConnection.setRequestProperty("User-Agent","NetFox"); k@:M#?(F  
String sProperty = "bytes="+nStartPos+"-"; Bu_/yKW  
httpConnection.setRequestProperty("RANGE",sProperty); y.vYT{^  
Utility.log(sProperty); M~/7thP{  
R<(kiD\?]  
{;mT.[  
InputStream input = httpConnection.getInputStream(); t7#lRp&  
//logResponseHead(httpConnection); r'*x><m'  
3kqO5+,C  
KTLq~Ru  
byte[] b = new byte[1024]; Rn?Yz^ 1q  
int nRead; 3lr9nBR  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u*}[fQ`aF  
{ ]6s7?07m4  
nStartPos += fileAccessI.write(b,0,nRead); 8.JFQ/) i  
//if(nThreadID == 1) $[(amj-;l  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 76 nrDE  
}  \EI<1B  
J34/rL/s  
3QSA|  
Utility.log("Thread " + nThreadID + " is over!"); ,jH<i.2R  
bDownOver = true; 3T1t !q4/5  
//nPos = fileAccessI.write (b,0,nRead); m{#?fR=9  
} ;|yd}q=p  
catch(Exception e){e.printStackTrace ();} J n>3c  
} P'}WmE'B}F  
} 2:[ -  
J:D{5sE<|  
[7Fx#o=da  
//打印回应的头信息 r{LrQ  
public void logResponseHead(HttpURLConnection con) }`fFzb  
{ 96ydcJY0'  
for(int i=1;;i++) @~p;.=1]F  
{ y-#{v.|L  
String header=con.getHeaderFieldKey(i); k]>1@t  
if(header!=null) WzinEo{ f  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oz8z%*9 (  
Utility.log(header+" : "+con.getHeaderField(header)); #Sg< 9xsW  
else [p Y1\$,  
break; dMd2a4  
} b6(LoN.  
} h95a61a,Vy  
W0-KFo.'  
9N[(f-`  
public void splitterStop() "%zb>`1s  
{ t@(:S6d  
bStop = true; t_xO-fT)  
} S"=y >.#  
L/Tsq=  
3bsuE^,.@  
} u B~C8}  
)70i/%}7  
reP)&Fo  
/* VsU*yG a  
**FileAccess.java o|en"?4  
*//文件访问(定位,写) /E %^s3S.  
package NetFox; g$/C-j4A[  
import java.io.*; |7CFm  
C(Cuk4K  
tRZA`&  
public class FileAccessI implements Serializable{ Qr.SPNUFK  
 Uf,fd  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l@W1b S  
RandomAccessFile oSavedFile; *DDqa?gQb  
long nPos; b}APD))*H!  
HpKF7oJ'N  
7jS`4,  
public FileAccessI() throws IOException HuI?kLfj\  
{ UwtL v d  
this("",0); 5mqwNAv  
} 'g5 Gdn  
UG !+&ii|  
90Sp(  
public FileAccessI(String sName,long nPos) throws IOException [ !<  
{ 0Z4o3r[  
oSavedFile = new RandomAccessFile(sName,"rw"); w;p~|!  
this.nPos = nPos; alp}p  
oSavedFile.seek(nPos); P:OI]x4  
} ).$q9G  
,&F4|{  
sx^0*h-Qq  
public synchronized int write(byte[] b,int nStart,int nLen) -dyN Ah?=  
{ x=I|O;"><  
int n = -1; 5 (cgHr"  
try{ 5>x?2rp  
oSavedFile.write(b,nStart,nLen); ^yFtL(x,  
n = nLen; Ze.\<^-t  
} Vi*HG &DD  
catch(IOException e) (3VV(18  
{ ~PZIYG"D  
e.printStackTrace (); AZH= r S`  
} ]EWEW*'j  
U(6=;+q  
I xk+y?  
return n; MszX9wl  
} al1Nmc #  
hk.vBbhs  
o;"Phc.  
} PdD,~N#  
($T"m-e  
elDt!9Pu  
/* _&R lR  
**SiteInfoBean.java #qDMUN*i  
*/ (:r80:  
package NetFox; %~rXJrK  
MJ_]N+  
)|N_Q}  
public class SiteInfoBean { V`& O`  
i"RBk%  
g4f:K=5:  
private String sSiteURL; //Site's URL o,gH*  
private String sFilePath; //Saved File's Path e. '6q ($3  
private String sFileName; //Saved File's Name -d)+G%{  
private int nSplitter; //Count of Splited Downloading File p0sq{d~  
o>jM4sk$  
Ad)::9K?J  
public SiteInfoBean() 6 k+4R<  
{//nSplitter的缺省值为5 "CY#_)  
//default value of nSplitter is 5 Wi2Tg^  
this("","","",5); > }fw7X  
} Bm$(4  
_^MkC} 8  
* LOUf7`  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1+ib(MJ<:#  
{ hM "6-60  
sSiteURL= sURL; AI,Jy%62/  
sFilePath = sPath; AD>X'J u8  
sFileName = sName; zI{~;`tzN  
this.nSplitter = nSpiltter; vE{L`,\ q  
$2/v8  
]L/AW  
} krMO<(x+  
Ba#wW E  
chakp!S=  
public String getSSiteURL() k];NTALOG  
{ )cV*cDL1j  
return sSiteURL; sLze/D_M*  
} kCHYLv3.  
tl"?AQcBR  
QzilivJf  
public void setSSiteURL(String value) yFY:D2  
{ l|j}Ggen  
sSiteURL = value; yp?a7t M  
} EWC{896,  
uA;vW\fHr  
C8W4~~1S  
public String getSFilePath() 9D[Jn}E:  
{ 73kU\ux  
return sFilePath; 0WI@BSHnM  
} HY2*5 #T  
7'zXf)!  
NbPNcjPL  
public void setSFilePath(String value) ^\Epz* cL  
{ e1/{bX5  
sFilePath = value; AU 4K$hC^  
} t.pn07$  
z(eAhK}6?  
AlA:MO]NM  
public String getSFileName() f)19sjAJk  
{ ~A@HW!*Z@  
return sFileName; lPZYd 8  
} +x]3 - s  
<`?V:};Q  
qAW?\*n5N  
public void setSFileName(String value) TD-o-*mO  
{ EECuJ+T  
sFileName = value; 2(i| n=  
} ?k$'po*Eq  
y8j6ttQv=t  
RdqB^>X  
public int getNSplitter() ac!!1lwA  
{ YhQ%S}  
return nSplitter; N;S1s0FN  
} {1;R&  
qO{Yr$ V%  
N4)ZPLV  
public void setNSplitter(int nCount) *Xl,w2@  
{ kp3%"i&hD  
nSplitter = nCount; 3 =-V!E  
} K_ Odu^  
} @p<tJR"M  
]sZ! -q'8  
Seh(G  
/* ]Ns)fr 6  
**Utility.java > JV$EY,  
*/ YL&)@h  
package NetFox; Q!y%N&  
`8/D$  
J%FF@.)k  
public class Utility { ;6M [d  
K$KVm^`  
lWakyCS  
public Utility() {I8C&GS  
{ W1_.wN$,5  
x|$|~ 6f=n  
4n} a%ocv^  
} K05U>151  
.'PS L  
//线程睡眠 6d(D >a  
public static void sleep(int nSecond) I8f='  
{ C`=YGyj=TL  
try{ U:0Ma 6<  
Thread.sleep(nSecond); ^*"i *e  
} >%H(0G#X  
catch(Exception e) 2b K1.BD  
{ /B<QYvv  
e.printStackTrace (); K%ptRj$  
} SQ DfDrYP  
} rXR!jZ.hi  
g OK   
//日志 $`[TIyA9!  
public static void log(String sMsg) d:pGdr& .  
{ s_}`TejK  
System.err.println(sMsg); cH6++r  
} :-Ml?:0_X  
[@_W-rA  
{fJCj152.  
public static void log(int sMsg) d7S?"JpV  
{ &y&HxV  
System.err.println(sMsg); r+k g$+%b  
} [\qclW;L  
} saTS8p z  
^yX>^1  
S,x';"  
/* HR ;I}J 9  
**TestMethod.java _2TL>1KZt  
*/ 1Qw_P('}  
package NetFox; 55FRPNx-x  
sC A  
=Z ql6D  
public class TestMethod { szCB}WY  
dNf:I,<DCf  
)|/%]@` N  
public TestMethod() g`C\pdX"B  
{ ///xx/weblogic60b2_win.exe V8#NXU g<!  
try{ oFGWI#]ts>  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >a&IFi,j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t.#ara{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); '<s54 Cb  
fileFetch.start(); J0Gjo9L  
} \CX6~  
catch(Exception e){e.printStackTrace ();} adPd}rt;  
L2=:Nac  
( k,?)  
} zdm2`D;~p  
=*R6 O,  
_+.JTk  
public static void main(String[] args) q ~^!Ck+#*  
{ j^%N:BQ&  
new TestMethod(); \ef:H&r  
} b:cy(6G(  
} BOWOH  
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