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http断点续传简单实现(java)

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/* 6}I X{nQI  
**SiteFileFetch.java Pa Q lQ#  
*/ z/4<x?}+hE  
package NetFox; ^0|:  
import java.io.*; \&kj#)JYA  
import java.net.*; N~=PecQ  
TaYl[I  
8=L"rekV_  
public class SiteFileFetch extends Thread { <dP \vLH_  
qsoq1u,?  
:s_.K'4?a  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^_@[1'^  
long[] nStartPos; //开始位置 OeASB}  
long[] nEndPos; //结束位置 ^P~,bO&H.Z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !;&\n3-W  
long nFileLength; //文件长度 JYw?  
boolean bFirst = true; //是否第一次取文件 V{oFig 6  
boolean bStop = false; //停止标志 i *:QbMb  
File tmpFile; //文件下载的临时信息 Gn^lF7yE  
DataOutputStream output; //输出到文件的输出流 tkk8b6%h?p  
jnOnV1I"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) p1d%&e  
public SiteFileFetch(SiteInfoBean bean) throws IOException G) KI{D  
{ v.8kGF  
siteInfoBean = bean; iy]L"7&Z2  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 80lhhqRC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); fn 'n'X|  
if(tmpFile.exists ()) lq_UCCnv5  
{ ck0%H#BYY  
bFirst = false; hu0z 36  
read_nPos(); Q ]TZyk  
} <t(H+ykh  
else 2_u+&7  
{ +8Q @R)3  
nStartPos = new long[bean.getNSplitter()]; J61%a,es  
nEndPos = new long[bean.getNSplitter()]; BZ.l[LMp  
} ej_u):G*  
v]on0Pi!  
!c)F;  
l#v52  
} ',`Qx{tQ)  
J#Y0R"fo  
8Pd9&/Y  
public void run() ~;$QSO\2h  
{ X);'[/]E*  
//获得文件长度 Brs6RkRf  
//分割文件 Conik`  
//实例FileSplitterFetch ~{{S<S v  
//启动FileSplitterFetch线程 Lb Jf5xdi  
//等待子线程返回 w?u3e+  
try{ g#74c'+  
if(bFirst) @Hp%4$=  
{ ,\ 1X\  
nFileLength = getFileSize(); I$sXbM;z=  
if(nFileLength == -1) &8i$`6wY  
{ FXT^r3  
System.err.println("File Length is not known!"); ]}'bRq*]  
} q M_c-^F  
else if(nFileLength == -2) 1ED7 .#g  
{ _y6iR&&x  
System.err.println("File is not access!"); M .6BFC  
} Xa>'DO2  
else `,~'T [  
{ T&/ n.-@nk  
for(int i=0;i<nStartPos.length;i++) qm/>\4eLt  
{ UZFs ]z!,k  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }XUI1H]jk  
} i^:#*Q-co  
for(int i=0;i<nEndPos.length-1;i++)  1hi  
{ aO}hE 2]  
nEndPos = nStartPos[i+1]; w6> P[oW  
} %k?/pRv$>  
nEndPos[nEndPos.length-1] = nFileLength; y,rdyt  
} rd%uc~/  
} p9G+la~;VM  
|PYyhY  
99:.j=  
//启动子线程 ))dqC l  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E71H=C 4  
for(int i=0;i<nStartPos.length;i++)  ZaaBg  
{ M9fQ,<c<6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !!ZGNZ_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Qh8pOUD0l}  
nStartPos,nEndPos,i); C[Q4OAFG  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Xsanc@w)^C  
fileSplitterFetch.start(); /#{~aCOi)  
} &m36h`tM  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1Z_w2D*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ux^ue9  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uIO?4\s&G  
nEndPos = " + nFileLength); %/\sn<6C}  
// fileSplitterFetch[nPos.length-1].start(); Vr& GsT  
hJ%$Te  
X xwcvE  
//等待子线程结束 hEo$Jz`  
//int count = 0; lUq `t K8  
//是否结束while循环 $aT '~|?  
boolean breakWhile = false; YwH Fn+  
0wqw5KC  
tr0kTW$Ad  
while(!bStop) m7A3i<6p  
{ \cX9!lHl  
write_nPos(); Y@UW\d*'%I  
Utility.sleep(500); =7kn1G.(  
breakWhile = true; ?G9DSk?6%Z  
PQF 40g1}  
1bw$$QXC_  
for(int i=0;i<nStartPos.length;i++) NODg_J~T  
{ wS$ 'gKA6  
if(!fileSplitterFetch.bDownOver) N1y,~Z  
{ `;R$Ji=>  
breakWhile = false; P^q!Pye  
break; Fm&f  
}  iSX:H;  
} r da: ~  
if(breakWhile) ESIeZhXVH  
break; =b)!l9TX  
&432/=QSm0  
tmoclK-  
//count++; =NK'xPr  
//if(count>4) %qrUP\rn  
// siteStop(); P?8$VAkj  
} ]-heG'y]{  
BdvpG  
g[ @Q iy  
System.err.println("文件下载结束!"); d[;&2Jz*  
} VJr~h "[  
catch(Exception e){e.printStackTrace ();} HDE5Mg "  
} Yu[MNX ;G  
3$_- 0>  
'wBOnGi6  
//获得文件长度 "Rf|o 6!d  
public long getFileSize() JNvgUb'U  
{ 51AA,"2[_  
int nFileLength = -1; Mg^A,8lrm  
try{ $`C$|9S  
URL url = new URL(siteInfoBean.getSSiteURL()); xo-}t5w6t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5Ktll~+:#  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZWB3R  
axXR-5c  
=(,kjw88w  
int responseCode=httpConnection.getResponseCode(); op&j4R  
if(responseCode>=400) QS,_=< (  
{ s9u7zqCF  
processErrorCode(responseCode); Z#;\Rb.x7  
return -2; //-2 represent access is error C}o^p"M*B3  
} 1iM(13jW  
d(Yuz#Qcrh  
?IO3w{fmH  
String sHeader; 4!M0)Nix  
eNFA.*p<  
=k!F`H`/%'  
for(int i=1;;i++) `;Fs  
{ D/2;b;-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qV$0 ";d  
//Utility.log(in.readLine()); Zc9S[ivq  
sHeader=httpConnection.getHeaderFieldKey(i); c-?0~A  
if(sHeader!=null) xaIe7.Z"xo  
{ PB{5C*Y7^k  
if(sHeader.equals("Content-Length")) T(kG"dz   
{ /hGu42YG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0}Q d  
break; HN&]`cr;  
} 8 vvNn>Q  
} }OgZZ8-_M  
else 3KKq1][  
break; f(-3d*g  
} Xu{S4#1  
} r?Pk}Q  
catch(IOException e){e.printStackTrace ();}  OF( tCK  
catch(Exception e){e.printStackTrace ();} yMb.~A^$J  
lR]SGdY  
5PKdMEK|q  
Utility.log(nFileLength); <QK2Wc_}-"  
;q2e[y  
qd [Z\B  
return nFileLength; B o[aiT  
} 04#r'UIF  
ZV:0:k.x  
?uE@C3 e  
//保存下载信息(文件指针位置) be&,V_F  
private void write_nPos() Snas:#B!  
{ 'n!Sco)C  
try{ 7t/C:2^&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Io)@u~yz  
output.writeInt(nStartPos.length); ?OWJUmQ  
for(int i=0;i<nStartPos.length;i++) t. kOR<  
{ |uln<nM9  
// output.writeLong(nPos); %R*-oQ1T  
output.writeLong(fileSplitterFetch.nStartPos); v6KF0mqA&  
output.writeLong(fileSplitterFetch.nEndPos); ljO t~@Ea  
} -(![xZ1{K  
output.close(); 4kf8Am(  
} C C`Y r  
catch(IOException e){e.printStackTrace ();} +C9 l7 q  
catch(Exception e){e.printStackTrace ();} RD'i(szi?  
} %3 $EV}dp  
ns !Mqcm  
kT4Tb%7KM  
//读取保存的下载信息(文件指针位置) 1bJrEXHXy  
private void read_nPos() A{QA0X!p  
{ AU^5N3%j  
try{ Fop'm))C8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p EbyQ[  
int nCount = input.readInt(); ioS(;2F  
nStartPos = new long[nCount]; y[sO0u\  
nEndPos = new long[nCount]; 7 a_99? J  
for(int i=0;i<nStartPos.length;i++) =G%L:m*  
{ =LMM]'no,  
nStartPos = input.readLong(); d,caOE8N  
nEndPos = input.readLong(); )*n2 ,n  
} @t?uhT*Z=  
input.close(); O0 ,=@nw8.  
} |4|j5<5  
catch(IOException e){e.printStackTrace ();} `%S#XJU  
catch(Exception e){e.printStackTrace ();} %w3"B,k'9D  
} Omy<Y@$  
)wueR5P  
E(G&mfhb  
private void processErrorCode(int nErrorCode) $fl+l5?9  
{  a EmLf  
System.err.println("Error Code : " + nErrorCode); ,fW%Qv  
} C{8(ew  
lr_c  
P+t`Rw  
//停止文件下载 Ov PTgiI!N  
public void siteStop() "s5[w+,R  
{ @fG 'X  
bStop = true; rW B/#m  
for(int i=0;i<nStartPos.length;i++) Dk`(Wgk2  
fileSplitterFetch.splitterStop(); r:Rk!z*  
}:a:E~5y  
8[xl3=  
} EgT?Hvx:  
} @Lf-=9  
//负责部分文件的抓取 g<$q#l~4xH  
**FileSplitterFetch.java TQg~I/  
*/ %#$K P  
package NetFox; U[t/40W}P  
xb~8uD5  
@j|=M7B  
import java.io.*;  c 1o8   
import java.net.*; 6@; P  
#:LI,t  
 d| OEZx  
public class FileSplitterFetch extends Thread { $I }k>F  
DZE@C^ 0%  
_?QVc0S!  
String sURL; //File URL #9ZHt5T=$  
long nStartPos; //File Snippet Start Position x|lX1Mh$  
long nEndPos; //File Snippet End Position }*9mNE  
int nThreadID; //Thread's ID \olYv!f  
boolean bDownOver = false; //Downing is over I$w:qS&:  
boolean bStop = false; //Stop identical Iu|4QE  
FileAccessI fileAccessI = null; //File Access interface pDV8B/{  
A{Dy3tm=  
/@QPJ~%8Ud  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @pkQ2OM 2  
{ Usz O--.C  
this.sURL = sURL; >#~>!cv6D  
this.nStartPos = nStart; YwnYTt  
this.nEndPos = nEnd; oZwu`~h Y  
nThreadID = id; hWD%_"yhd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -b$m<\0*  
} FH7h?!|t  
ee\QK,QV  
#$0*Gd-N  
public void run() !}PZCbDhL  
{ B Ms?+  
while(nStartPos < nEndPos && !bStop) w9]HJ3qi  
{ 2U.'5uA"L  
;G|#i? JJ  
' >R?8Y  
try{ x,:DL)$1  
URL url = new URL(sURL); 5~GH*!h%;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,zVS}!jRhy  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]m<z  
String sProperty = "bytes="+nStartPos+"-"; >&%#`PKT  
httpConnection.setRequestProperty("RANGE",sProperty); q)PLc{NO  
Utility.log(sProperty); Bx 9v2x.  
d.Ep#4  
GLWEoV9<  
InputStream input = httpConnection.getInputStream(); $@^*lUw  
//logResponseHead(httpConnection); v1}9i3Or#  
5DxNHEuS  
13K|=6si  
byte[] b = new byte[1024]; ^n~bx *f  
int nRead; 1'4?}0Dok  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +LwwI*;b  
{ _{&bmE  
nStartPos += fileAccessI.write(b,0,nRead); =}UcYC6l  
//if(nThreadID == 1) =k^ d5  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hnBX enT6  
} @|'$k{i  
D A_}pS"  
wU(!fw\  
Utility.log("Thread " + nThreadID + " is over!"); *w$3/  
bDownOver = true; ]@{l<ExP  
//nPos = fileAccessI.write (b,0,nRead); 9oQ$w?=#$  
} PT39VI =  
catch(Exception e){e.printStackTrace ();} )0?u_Z]w9  
} -]<<}@NF  
} H[2W(q6  
%Hu?syo  
AjD? _DPc  
//打印回应的头信息 ,s`4k?y  
public void logResponseHead(HttpURLConnection con) 4@r76v}{  
{ c"lblt5  
for(int i=1;;i++) QERj`/g  
{ w:aV2  
String header=con.getHeaderFieldKey(i); A9Icn>3?`(  
if(header!=null) F[KM0t!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `G:I|=#w  
Utility.log(header+" : "+con.getHeaderField(header)); *aW:Z6N  
else QWwdtk  
break; )|wC 1J!L  
} =A{s,UP  
} Pl\NzB,`  
Ruv`yfQ  
)~-r&Q5d  
public void splitterStop() j: E3c\a  
{ ~E/=nv$  
bStop = true; r'4Dj&9Ac  
} N<b~,[yCd>  
T;]Ob3(BpW  
9Y@ eXP  
} z;MPp#Y  
o/ 7[ G  
^$X|Lq  
/* 34Cnbtq^  
**FileAccess.java "dT"6,  
*//文件访问(定位,写) 4Y1dkg1y  
package NetFox; GS7'pTsYH  
import java.io.*; M| Nh(kvH  
i[ >U#5  
U#&+n-npO  
public class FileAccessI implements Serializable{ OL%}C*Zq  
r*dNta<  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P)#h4|xZ  
RandomAccessFile oSavedFile; W 1u!&:O  
long nPos; 3y,2RernK  
'1(6@5tyWk  
JPHM+3v  
public FileAccessI() throws IOException L|L|liWd  
{ |sY  
this("",0); *[m:4\  
} t{QQ;'  
;mRZ_^V;  
~9xkiu5~  
public FileAccessI(String sName,long nPos) throws IOException ~y?Nn8+&f  
{ )EQz9  
oSavedFile = new RandomAccessFile(sName,"rw"); gwdAf%|f  
this.nPos = nPos; \.}ZvM$  
oSavedFile.seek(nPos); IUDH"~f  
} ~Uey'Xz  
ijUu{PG`X  
_/'VD!(MV  
public synchronized int write(byte[] b,int nStart,int nLen) T?QW$cU!e:  
{ @56*r@4:q  
int n = -1; lSlZ^.&  
try{ QnP?j&  
oSavedFile.write(b,nStart,nLen); G+Bk!o  
n = nLen; '2hy%  
} \#WWJh"W  
catch(IOException e) jvAjnh#  
{ ;]b4O4C\  
e.printStackTrace (); TLp2a<Iy  
} a DXaQ  
/qMnIo  
y:^o ._  
return n; /]_|uN)Q  
} j"hEs(t  
S3i p?9  
#oFyi @U  
} YM6 J:89  
FRajo~H  
)QRT/, ;c  
/* }mzd23^W>P  
**SiteInfoBean.java w-2#CX8jY  
*/ ExSM=  
package NetFox; F\^8k/0  
SDV#p];u  
LMx/0  
public class SiteInfoBean { $v[mIR  
D B65vM  
,|3_@tUl  
private String sSiteURL; //Site's URL ?o$ t{AQ  
private String sFilePath; //Saved File's Path ?|/K(}  
private String sFileName; //Saved File's Name e^3D`GA  
private int nSplitter; //Count of Splited Downloading File HA,8O [jon  
]jC{o,?s  
h#KSKKNW  
public SiteInfoBean() bmK  
{//nSplitter的缺省值为5 &VA^LS@b  
//default value of nSplitter is 5 71Za!3+  
this("","","",5); [Eccj`\e g  
} U._fb=  
> Xh=P%  
\#LDX,=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =}kISh  
{ mXyN{`q=  
sSiteURL= sURL; U;4i&=.!  
sFilePath = sPath; "uT2 DY[  
sFileName = sName; /RMtCa~  
this.nSplitter = nSpiltter; 4v |i\V>M  
D!! B4zt  
yYYP;N?g4k  
} ib#rT{e  
@'):rFr@F  
3<"j/9;K'  
public String getSSiteURL() @&`^#pok  
{ HR"clD\{Di  
return sSiteURL; ]u!s-=3s  
} ZJU %&@  
iQ(j_i'+!I  
_pZ <  
public void setSSiteURL(String value) A[^#8evaK  
{ - _ 8-i1?  
sSiteURL = value; *?d\Zcj85[  
} q~ Z UtF  
A{J?I:  
^)Awjj9  
public String getSFilePath() Yl>Y.SO  
{ (lS[a  
return sFilePath; ZD'mwj+K  
} `h'l"3l  
)^ZC'[93  
H v/5)  
public void setSFilePath(String value) fs;\_E[)  
{ > ^zNKgSQ  
sFilePath = value; 7gN;9pc$  
} pZopdEFDK|  
m(MQ  
ar\|D\0V  
public String getSFileName() d/j?.\  
{ >'W,8F  
return sFileName; cZ|NGkZ  
} ga/zt-&  
Zv!XNc!"$y  
;`LG WT-<F  
public void setSFileName(String value) ,$ /Ld76U  
{ GiX3c^V"1  
sFileName = value; MGMJeq vr  
} {*F =&D  
9x!kvB6  
xWXLk )A  
public int getNSplitter() @ Do.Wgt  
{ O50<h O]l  
return nSplitter; _b&26!gl  
} qpjZ-[UC  
U m\HX6  
.=Oww  
public void setNSplitter(int nCount) gBh X=2%  
{ zJW2F_  
nSplitter = nCount; >AX_"Q~  
} ZCj1Cz]"l<  
} SyI~iW#Y1  
Qt {){uE  
iTq&h=(n  
/* YcX"Z~O6j=  
**Utility.java TMY. z  
*/ A :KZyd"Z  
package NetFox; )Cj1VjAg  
M0xhcU_  
G.<0^q,  
public class Utility { $%\6"P/64  
qMVuFw Phi  
2"Wq=qy\J  
public Utility() q MrM^ ~  
{ VFZ?<m  
,M?8s2?  
8)?&eE'  
} n0co* ]X+k  
b<4nljbx  
//线程睡眠 Qd YYWD   
public static void sleep(int nSecond) ;@ixrj0u  
{ rZpsC}C'  
try{ c}n66qJF5  
Thread.sleep(nSecond); OYt_i'Q  
} 4hxP`!<  
catch(Exception e) zEO~mJzo  
{ '+{yg+#/wV  
e.printStackTrace (); yp$jLBA  
} -hW>1s<  
} Xwo+iZ(a  
X9|*`h<  
//日志 X)hpbHa  
public static void log(String sMsg) 1ow,'FztPt  
{ %.f%Q?P  
System.err.println(sMsg); |wv+g0]Pg^  
} , ~38IIS>_  
+`gU{e,p  
/{hT3ncb  
public static void log(int sMsg) [<U=)!Swg  
{ Ewr2popK  
System.err.println(sMsg); kI!@J6  
} ~!mY0odH  
} v{|y,h&]a  
CSoVB[vS  
KzV|::S^  
/* C^,b aCX  
**TestMethod.java "IQYy~ /  
*/ >SvS(N{  
package NetFox; mMllen  
nTo?~=b  
IFew3!{\  
public class TestMethod { qF$y p>|#  
QOUyD;0IW  
!2HF|x$  
public TestMethod() M0lJyz J  
{ ///xx/weblogic60b2_win.exe 0_ST2I"Ln  
try{ \.iejB  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p<'pqf  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5<`83; R9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); qzvht4  
fileFetch.start(); QeFt WjlqC  
} C4ktCN  
catch(Exception e){e.printStackTrace ();} qonStIP  
uwI"V|g%a&  
K]B`&ih  
} |pBFmm*  
:TP4f ?FA  
+{=U!}3|  
public static void main(String[] args) $eT[`r  
{ ./3/3& 6  
new TestMethod(); HxW/t7Z(  
} l lcq~*zz  
} Nb3O> &J  
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