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http断点续传简单实现(java)

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/* giddM2'  
**SiteFileFetch.java rPW 9lG  
*/ a5g1.6hF  
package NetFox; '_=XfTF  
import java.io.*; =)6|lz^  
import java.net.*; vs.}Bou]  
9EZh~tdV[  
zgpv I~Ck  
public class SiteFileFetch extends Thread { H&ZsMML/%  
\l;H !y[  
Q F_K^(  
SiteInfoBean siteInfoBean = null; //文件信息Bean $J:~jY/J  
long[] nStartPos; //开始位置 0jefV*3qpB  
long[] nEndPos; //结束位置 ws}>swR,  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 KI<Vvc m  
long nFileLength; //文件长度 dG]s_lb9H  
boolean bFirst = true; //是否第一次取文件 p@xK`=Urb  
boolean bStop = false; //停止标志 +@oo8io  
File tmpFile; //文件下载的临时信息 pK2n'4 C  
DataOutputStream output; //输出到文件的输出流 VrRBwvp-K  
RE:$c!E!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) {I_I$x_  
public SiteFileFetch(SiteInfoBean bean) throws IOException ? #;zB  
{ .We"j_ }  
siteInfoBean = bean; p>]2o\["  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }NJ? .Y  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); B,dKpz;kFg  
if(tmpFile.exists ()) s%qK<U4@;Q  
{ m&#a M8:\  
bFirst = false; Mio~CJ"?  
read_nPos(); M}6? |ir  
} C,m o4,Q  
else bQM_rqjJGw  
{ Aa/lKiiz  
nStartPos = new long[bean.getNSplitter()]; ((%g\&D  
nEndPos = new long[bean.getNSplitter()]; U~8 oE_+  
} _-I0f##.  
#G ZGk?  
~\m|pxcj  
a<X<hxW:  
} M e  
sj@'C@oK  
ojitBo~  
public void run() VXAgp6  
{ f&ym'S  
//获得文件长度 9f4#b8  
//分割文件 e$^O_e  
//实例FileSplitterFetch ou@ P#:<B  
//启动FileSplitterFetch线程 :bgi*pR{  
//等待子线程返回 q|%(47}z  
try{ s],+]<qX  
if(bFirst) ATU 2\Y  
{ 8W"~>7/>D  
nFileLength = getFileSize(); xCV3HnZ  
if(nFileLength == -1) c.PPVqx  
{ z<jWy$Ta;  
System.err.println("File Length is not known!"); q<b;xx  
} r,x;q  
else if(nFileLength == -2) eID"&SSU  
{ toEmIa~o6  
System.err.println("File is not access!"); Hdh'!|w  
} s!2pOH!u   
else V4!RUqK  
{ !R WX1Z  
for(int i=0;i<nStartPos.length;i++) -_ [Z5%B  
{ e}e\*BL  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); P~:W+!@5v  
} 16YJQ ue  
for(int i=0;i<nEndPos.length-1;i++) QP?Z+P<  
{ Nze#u;  
nEndPos = nStartPos[i+1]; 7@m  
} U&/Jh^Yy  
nEndPos[nEndPos.length-1] = nFileLength; lV^sVN Z]  
} c;ELAns>  
} Kl$!_$  
n}yqpW!%n  
eGblQGRS  
//启动子线程 #uT-_L}s w  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^m{kn8  
for(int i=0;i<nStartPos.length;i++) '@Y@H,  
{ %u43Pj  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JF_\A)<ki  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Bj J$I^  
nStartPos,nEndPos,i); ])a?ri  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5Y)!q?#H  
fileSplitterFetch.start(); ^;$f-e  
} BRV /7ao="  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .)B_~tct  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~-6Kl3Y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >0i?}  
nEndPos = " + nFileLength); ^owEB%  
// fileSplitterFetch[nPos.length-1].start(); 9+SeG\Th  
%"DEgI P  
BJk\p.BVN  
//等待子线程结束 {`~{%2ayq7  
//int count = 0; Om{[ <tL  
//是否结束while循环 ![:S~x1  
boolean breakWhile = false; E'&UWD h  
j 46f Q  
lbgnO s,  
while(!bStop) M:nXn7)+  
{ ((Ec:(:c  
write_nPos(); .7Ys@;>B  
Utility.sleep(500); co<){5zOT  
breakWhile = true; l@<^V N@  
OtF{=7  
]ODC+q1  
for(int i=0;i<nStartPos.length;i++) 5}~*,_J2Z  
{ C_PXh>H]'  
if(!fileSplitterFetch.bDownOver) <h U ZD;  
{ d^Ra1@0"q2  
breakWhile = false; <{YP=WYW  
break; 23y7l=.b/  
} DhY9)>4M  
} )Bl% {C  
if(breakWhile) HQaKG4Z  
break; \h :Rw|  
IL}pVa00{n  
c$?qN&X_K  
//count++; g;\zD_":l  
//if(count>4) . %tc7`k8  
// siteStop(); \"_;rJ{!aE  
} o]MQ)\ r  
s:R>uGYOd  
3oxQ[.o  
System.err.println("文件下载结束!"); @+ Berb  
} *A GC[w}/  
catch(Exception e){e.printStackTrace ();} A,lcR:@w  
} mv SNKS  
7u!R 'D  
3l`yy])t  
//获得文件长度 Rr4r[g#  
public long getFileSize() .+ai dWd  
{ 15 uVvp/  
int nFileLength = -1; zBB4lC{q  
try{ - CT?JB  
URL url = new URL(siteInfoBean.getSSiteURL()); {TzKHnP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i<bFF03*S  
httpConnection.setRequestProperty("User-Agent","NetFox"); A7+eWg{  
uMPJ  
5^GUuFt5m  
int responseCode=httpConnection.getResponseCode(); ^%#v AS  
if(responseCode>=400) :8E(pq|1PB  
{ isDBNXV:  
processErrorCode(responseCode); HHWB_QaL  
return -2; //-2 represent access is error h k(2,z  
} 4eBM/i  
"]*0)h_  
g?^o++  
String sHeader; O#Xq0o  
+To{Tm-  
Nypa,_9}  
for(int i=1;;i++) +S^Uw'L$=T  
{ T"in   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2Ev~[Hb.  
//Utility.log(in.readLine()); rbO9NRg>  
sHeader=httpConnection.getHeaderFieldKey(i); _s|C0Pt  
if(sHeader!=null) WkXa%OZ  
{ Sw%=/g  
if(sHeader.equals("Content-Length")) p!|Wp  
{ rm+|xvZ4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); EtcAU}9  
break; P9G c)$6{p  
} x}AWWmXv  
} g>/,},jv[x  
else UXDd8OJL  
break; eMPi ho  
} Q;)[~p  
} ~U~KUL|  
catch(IOException e){e.printStackTrace ();} %^2LTK(P  
catch(Exception e){e.printStackTrace ();} ,Tvk&<!0  
=>)l6**UE  
80![aj}z4G  
Utility.log(nFileLength); ~>k<I:BtrT  
jXSo{  
&Jk0SUk MP  
return nFileLength; $FNj>1  
} ht!o_0{~  
5^ARC^v  
+Z/ *=;  
//保存下载信息(文件指针位置) P"XF|*^U  
private void write_nPos() -3_-n*k!  
{ QO[!  
try{ \WQ\q \  
output = new DataOutputStream(new FileOutputStream(tmpFile)); =n cu# T]  
output.writeInt(nStartPos.length); #i%it  
for(int i=0;i<nStartPos.length;i++) #:3ca] k  
{ r0+lH:G*q  
// output.writeLong(nPos); jdK~]eld=  
output.writeLong(fileSplitterFetch.nStartPos); P5P:_hr  
output.writeLong(fileSplitterFetch.nEndPos); #OqQD6  
} AT<K>&)  
output.close(); +j1s*}8  
} "|{ NRIE  
catch(IOException e){e.printStackTrace ();} &-:ZM0Fl  
catch(Exception e){e.printStackTrace ();} M56^p ,  
} P%8 Gaa=  
X#EMmB!  
='`z  
//读取保存的下载信息(文件指针位置) ZNuz%VO  
private void read_nPos() 3=RVJb  
{ Q })x4  
try{ 6NPCp/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O:IU|INq8  
int nCount = input.readInt(); ` .|JTm[  
nStartPos = new long[nCount]; f=+|e"i #p  
nEndPos = new long[nCount]; umaF}}-Q{  
for(int i=0;i<nStartPos.length;i++) 4/;hA z  
{ 8UJK]_99I,  
nStartPos = input.readLong(); ]P;uQ!  
nEndPos = input.readLong(); %PRG;kR  
} 9t:F![rg  
input.close(); B 7zyMh   
} = NHuj.  
catch(IOException e){e.printStackTrace ();} ##+|zka!U  
catch(Exception e){e.printStackTrace ();} }TY}sr  
} G0oY`WXOB  
mk(O..)2  
GqMa|8j  
private void processErrorCode(int nErrorCode) $M{MOehZ  
{ /j/,@,lw7z  
System.err.println("Error Code : " + nErrorCode); *oopdGue  
} 0zQ"5e?qy  
6_]-&&Nr  
'w3BSaJi  
//停止文件下载 3#N'nhUzA  
public void siteStop() t5t,(^;f  
{ RfH.WXi  
bStop = true; C))5,aX  
for(int i=0;i<nStartPos.length;i++) ~A@T_ *0  
fileSplitterFetch.splitterStop(); i[_ (0P+Da  
uu ahR  
x93h{K f  
} Z6s-n$dSm  
} '!eg9}<  
//负责部分文件的抓取 )4:K@  
**FileSplitterFetch.java =1Nz* c  
*/ 1(%9)).K  
package NetFox; EQe!&;   
T8<pb^#  
f@S n1c,Mk  
import java.io.*; YnM&t ;TX  
import java.net.*; .#^ta9^t7  
kw)( "SQ  
 N>ncv  
public class FileSplitterFetch extends Thread { mj{B_3b5  
`HVS}}{a  
w O H{L  
String sURL; //File URL -R %T Dx  
long nStartPos; //File Snippet Start Position d}D%%noIu  
long nEndPos; //File Snippet End Position o\/&05rp]  
int nThreadID; //Thread's ID #(@!:f1  
boolean bDownOver = false; //Downing is over *JnY0xP  
boolean bStop = false; //Stop identical ~6{iQZa1Y  
FileAccessI fileAccessI = null; //File Access interface 8;PS>9<  
E_q/*}]pE  
\c ')9g@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HQp\0NC]  
{ q+iG:B/Z  
this.sURL = sURL; pbCj ^  
this.nStartPos = nStart; B":9C'tip  
this.nEndPos = nEnd; 87!D@Xn  
nThreadID = id; / esdtH$=  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TWzlF>4N  
} cI Sugk~  
su$IXI#R-&  
gB _/(  
public void run() 6a*?m{  
{ dU}Cb?]7s  
while(nStartPos < nEndPos && !bStop) D\:dn  
{ ]I,(^Xq3a(  
e{Q;,jsh  
]?< wUd  
try{ Z8Iqgz7|y  
URL url = new URL(sURL); +3yG8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e{EC# %x_  
httpConnection.setRequestProperty("User-Agent","NetFox"); 7vo8lnQ{  
String sProperty = "bytes="+nStartPos+"-"; -F. c<@*E  
httpConnection.setRequestProperty("RANGE",sProperty); >jU25"XI[  
Utility.log(sProperty); zif&;)wV/  
a}e GB +  
~8 B]  
InputStream input = httpConnection.getInputStream();  /!#A'#Z  
//logResponseHead(httpConnection); _<E.?K$gbU  
A"e4w?  
0BwxPD#6bv  
byte[] b = new byte[1024];  )[S#:PP  
int nRead; j.&Y'C7GOC  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) oE.Ckz~*d  
{ {q/;G!ON.S  
nStartPos += fileAccessI.write(b,0,nRead); 216`rQ}z  
//if(nThreadID == 1) +v2)'?BS  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vbD""  
} {Gr"lOi*@  
3'Hz,qP  
Kv9$c(~#  
Utility.log("Thread " + nThreadID + " is over!"); zv7)JH7EV&  
bDownOver = true; lak,lDt]  
//nPos = fileAccessI.write (b,0,nRead); b'ZzDYN  
} { 2%'=v  
catch(Exception e){e.printStackTrace ();} F pT$D  
} f\rE{%  
} d,b]#fj  
k|czQ"vaI  
dB)-qL8,2  
//打印回应的头信息 :GN++\ 1pw  
public void logResponseHead(HttpURLConnection con) e-Oz`qW~  
{ eslvg#Q  
for(int i=1;;i++) gyQPQ;"H$2  
{ <PFF\NE9  
String header=con.getHeaderFieldKey(i); Q #X'.](1  
if(header!=null) l^XOW- ;u  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S n<X   
Utility.log(header+" : "+con.getHeaderField(header)); ;PB_ @Zg  
else +I\54PBws  
break; x=Aq5*A0  
} S&'?L0  
} J )^F  
VP~(;H5%  
)QW hzY  
public void splitterStop() -dWg1`;  
{ ^D1gcI  
bStop = true; l1#.r g  
} fLpWTkr0  
Yi]`"\  
8f<y~L_(`  
} k+%&dEE|vH  
lX-i<0`  
o*artMkG  
/* fJP *RVz  
**FileAccess.java +0 }_X  
*//文件访问(定位,写) C(9"59>{]y  
package NetFox; c3Gy1#f:#2  
import java.io.*; (/0dtJ  
fdWqc_  
CPL,QVO9  
public class FileAccessI implements Serializable{ ?E_;[(Mcr  
/\_n5XI1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i6A9|G$H  
RandomAccessFile oSavedFile; 6" <(M@  
long nPos; yf;TIh%)=  
<[D>[  
ar\ K8mj  
public FileAccessI() throws IOException D)pTE?@W'  
{ j>e RV ol  
this("",0); 0{uaSR  
} 3u/AqL  
O) TS$  
?;_>BX|Zjl  
public FileAccessI(String sName,long nPos) throws IOException rQ_]%ies8  
{ n((A:b  
oSavedFile = new RandomAccessFile(sName,"rw"); a|= ^   
this.nPos = nPos; w3"L5;oH  
oSavedFile.seek(nPos); lz ::6}  
} ?pfr^ !@$  
G&Dl($  
J^ewG  
public synchronized int write(byte[] b,int nStart,int nLen) dCS f$5  
{ qrp@   
int n = -1; +}M3O]?4  
try{ 7)Vbp--b#  
oSavedFile.write(b,nStart,nLen); lZ7 $DGe  
n = nLen; <xF]ca  
} T)OR HJ&,  
catch(IOException e) Vs{\ YfF  
{ x~R,rb   
e.printStackTrace (); uDXV@;6<  
} |,5|ZpgL  
nw% 9Qw  
b}ya9tCl;  
return n; D*[J rq,  
} F[$cE  
s2NBYDi$?  
kE .4 #  
} NU?<bIQ  
"O0xh_Nr  
ls&H oJ7  
/* c`p '5qz  
**SiteInfoBean.java Jy% ?"wn  
*/ LtX53c  
package NetFox; Y1I)w^}:  
_fu <`|kc  
+x}9a~QG#  
public class SiteInfoBean { ;>jEeIlT  
b^C27s  
=t)qy5  
private String sSiteURL; //Site's URL <7F-WR/2n  
private String sFilePath; //Saved File's Path T:Nk9t$W7@  
private String sFileName; //Saved File's Name u "jV#,,  
private int nSplitter; //Count of Splited Downloading File +Tu?PuT7k  
r>FwJm!  
oV0 45G  
public SiteInfoBean() ls:oC},p*  
{//nSplitter的缺省值为5 ]q{_i   
//default value of nSplitter is 5 NT.#U?9c  
this("","","",5); kt)Et  
} ?@,EGY <  
~Ay)kv;  
;J,(YNI 1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2<I=xWwFA  
{ z5]6"v -  
sSiteURL= sURL; c_*w<vJ-'  
sFilePath = sPath; /CNsGx%%  
sFileName = sName; _8u TK%|  
this.nSplitter = nSpiltter; <JWU@A-.y  
n]' r3  
$$NWN?H~  
} -i2rcH  
 )^{}ov  
8R3{YJ6@T  
public String getSSiteURL() Fb]+h)on  
{ +`k30-<P  
return sSiteURL; N~8H\  
} MVzuE}  
+:;ddV  
HbA/~7  
public void setSSiteURL(String value) vnvpb! @Q  
{ dE_Xd :>  
sSiteURL = value; mYgfGPF`  
} {V QGfN  
Z5 IWoY  
5N|LT8P}Z  
public String getSFilePath() Cj8&wz}ez  
{ js81@WX!c  
return sFilePath; .<`)`:n+B  
} xjo`u:BH  
.u&xo{$'dS  
hYkk r&  
public void setSFilePath(String value) /#Aw7F$Ey  
{ ZDFq=)0C  
sFilePath = value;  *XhlIQ  
} r/!,((Z\  
[_)`G*X(N  
'OtT q8G  
public String getSFileName() CwX?%$S   
{ F0U %m   
return sFileName; ]H n:c'aT  
} hc|A:v)]  
t`K9K"|k  
7y|U!r"Y  
public void setSFileName(String value) ZTzec zXpQ  
{ EE  1D>I  
sFileName = value;  <J;O$S  
} jV sH  
]XEyG7D  
1YV1 Xnn,  
public int getNSplitter() 6LDZ|K@  
{ CqnHh@]nu  
return nSplitter; Pw<?Dw]m  
} 71nZi`AR  
5qnei\~  
%1A8m-u]M  
public void setNSplitter(int nCount) oWY3dc  
{ 7#E/Q~]'6  
nSplitter = nCount; 9A.NM+u7  
} DS(>R!bb  
} aH6j,R%  
Wa^Wn +r  
*U1*/Q.  
/* `Vw G]2 I  
**Utility.java fYP,V0P  
*/ NRx 7S 9W  
package NetFox; @o0HDS  
^s6~*n<fH  
MM32\}Y6  
public class Utility { oYw?kxRZ  
j_rO_m<8  
PL= v,NB  
public Utility() $JOz7j(  
{ LOkgeJuWv  
RDbNC v#  
AJ/Hw>>$?m  
} Ms6 ;iW9  
3J"`mQ  
//线程睡眠 6Mc&=}bV  
public static void sleep(int nSecond) KcV"<9rE  
{ lD$s, hp  
try{ la{?&75]  
Thread.sleep(nSecond); V Dnrm*  
} }` 3-  
catch(Exception e) DL,R~  
{ X]}ai5  
e.printStackTrace (); )$^xbC#j`3  
} 28^/By:J  
} LBG`DYR@  
n/;{-  
//日志 h's[) t  
public static void log(String sMsg) ]B(}^N>WH  
{ .K~V DUu  
System.err.println(sMsg); i}LQ}35@  
} \)28,`  
^r}Uu~A>  
GThGV"  
public static void log(int sMsg) i-0 :Fs  
{ 8i "CU:(  
System.err.println(sMsg); ]Qe~|9I  
} a)2l9  
} 1W*Qc_5 v1  
E*)A!2rlK  
O8hx}dOjA  
/* XzV>q~I3|E  
**TestMethod.java !"phz&E5ah  
*/ CxaI@+  
package NetFox; jR1^e$  
lg-`zV3  
("A45\5  
public class TestMethod { wa[J\lW  
dh]Hf,OLF  
LGy6 2 y$  
public TestMethod() 3 a(SmM:  
{ ///xx/weblogic60b2_win.exe q:up8-LAr  
try{ o$bQ-_B`  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mKM[[l&A  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2O(k@M5E?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); br0\O  
fileFetch.start(); f(}&8~&  
} d+P<ce2 G  
catch(Exception e){e.printStackTrace ();} .))k  
"j`T'%EV  
M&zB&Ia"'  
} hDJ+Rk@  
.nr%c*JUp  
U#Kw+slM  
public static void main(String[] args) +:#g6(P]  
{ h Q Att  
new TestMethod(); zGO_S\  
} MAqETjB  
} \py&v5J)s!  
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