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http断点续传简单实现(java)

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/* ~_raI7,  
**SiteFileFetch.java 1)r1/0  
*/ Pwq} ;+  
package NetFox; GB+G1w  
import java.io.*; j.z#fU  
import java.net.*; `<K#bDU;a  
ecHy. 7H  
<W?,n%  
public class SiteFileFetch extends Thread { t`LH\]6@  
B4.hJZ5  
gs!{'=4wT  
SiteInfoBean siteInfoBean = null; //文件信息Bean iz'8P-]K>  
long[] nStartPos; //开始位置  *) wp  
long[] nEndPos; //结束位置 %:??QD*  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :>,d$f^tqE  
long nFileLength; //文件长度 53L)+\7w  
boolean bFirst = true; //是否第一次取文件 TqlUe@E  
boolean bStop = false; //停止标志 $Ec;w~e  
File tmpFile; //文件下载的临时信息 B8 2A:t)  
DataOutputStream output; //输出到文件的输出流 n\ IVpgP  
D^A_0@  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) P`"dj@1'  
public SiteFileFetch(SiteInfoBean bean) throws IOException sST6_b  
{ "evLI?  
siteInfoBean = bean; d`:0kOF+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); pZH bj2~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); >uQ!B/C!  
if(tmpFile.exists ()) J|ILG  
{ @<};Bo'  
bFirst = false; f6m^pbQFl  
read_nPos(); >V]> h&`  
} >Mn"k\j4  
else Oe5aNo  
{ :dK%=j*ZK  
nStartPos = new long[bean.getNSplitter()]; M0^r!f>O  
nEndPos = new long[bean.getNSplitter()]; !0w'S>e  
} [0 W^|=#K  
_z}d yp"I  
!{SEm"J^  
OnG!5b  
} KKOu":b  
/1O6;'8He  
K<V(h#(.@  
public void run() %';n9M  
{ K7CiICe  
//获得文件长度 c$@,*c 0n  
//分割文件 V ;"?='vVe  
//实例FileSplitterFetch >/ HC{.k  
//启动FileSplitterFetch线程 29x "E$e  
//等待子线程返回 DpI_`TF#$Z  
try{ 7u o4F= %  
if(bFirst)  ,Ad\!  
{ <f8@Qij  
nFileLength = getFileSize(); $(#o)r>_R  
if(nFileLength == -1) Qt]nlui~  
{ &!KJrQ  
System.err.println("File Length is not known!"); 8I NVn'G  
} C'*1w  
else if(nFileLength == -2) z&cfFx#h)  
{ :8yrtbf$  
System.err.println("File is not access!"); ~O |j*T  
} gd#  
else {l\v J#r:  
{ Xqf"Wx(X  
for(int i=0;i<nStartPos.length;i++) 7o0e j#  
{ ft:/-$&H  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); C Hyb{:<  
} (J$JIPF  
for(int i=0;i<nEndPos.length-1;i++) $N:m 9R  
{ LvhF@%(9J  
nEndPos = nStartPos[i+1]; lt5~rH2  
} tul5:}x3  
nEndPos[nEndPos.length-1] = nFileLength; JFR,QUT  
} |VaXOdD`&  
} }5zH3MPQH  
/DZKz"N  
+!.=M8[  
//启动子线程 jO!!. w  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b3y@!_'c  
for(int i=0;i<nStartPos.length;i++) }w"laZ*  
{ kmo3<'j{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gq+!%'][P  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i#(T?=VPcy  
nStartPos,nEndPos,i); ~;Xdz/  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a8A8?:  
fileSplitterFetch.start(); B>|@XfPM  
} o)Ob}j  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jw"'ZW#W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 83)2c a  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M6y:ze  
nEndPos = " + nFileLength); !3?HpR/nV  
// fileSplitterFetch[nPos.length-1].start(); *<s|WLMG  
CW, Kw  
0u)]1  
//等待子线程结束 d}ue/hdw  
//int count = 0; jJ|O]v$N  
//是否结束while循环 >(~; V;  
boolean breakWhile = false; C!~&c7  
GZ*cV3Y`&  
NWv1g{M  
while(!bStop) *jf (TIU  
{ 0u -'{6  
write_nPos(); 5 E DGl  
Utility.sleep(500); @/B&R^aVZ  
breakWhile = true; T4J (8!7  
xNE<$Bz  
~ hYG%  
for(int i=0;i<nStartPos.length;i++) H-^>Co_  
{ N[ E t  
if(!fileSplitterFetch.bDownOver) p>65(&N,  
{ dhsQfWg#}  
breakWhile = false; co@Q   
break; vYrqZie<  
} o;_v'  
} ^5j9WV  
if(breakWhile) OpUC98p?@  
break; h]vA%VuE'E  
iS=} | 8"  
WPpl9)Qc  
//count++; j`='SzVloW  
//if(count>4) (A/V(.!  
// siteStop(); ^hRos  
} MU%C_d%.  
N1+%[Uh9)  
[bH6>{3u  
System.err.println("文件下载结束!"); "4oY F:h  
} W@JmG`Sy  
catch(Exception e){e.printStackTrace ();} (lTM^3 }  
} g}P.ksM  
Abd&p N  
Z &/b p1  
//获得文件长度 |SQ5Sb  
public long getFileSize() \C~Y  
{ d%u|) =7  
int nFileLength = -1; bj ZcWYT  
try{ >N{K)a  
URL url = new URL(siteInfoBean.getSSiteURL()); (9{)4[3MAG  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '8}*erAg  
httpConnection.setRequestProperty("User-Agent","NetFox"); d^!)',`  
L6J=m#Ld  
 -*M/,O  
int responseCode=httpConnection.getResponseCode(); _U|s!60'  
if(responseCode>=400) ?8)_,  
{ }{J<Wzw  
processErrorCode(responseCode);  ntK#7(U'  
return -2; //-2 represent access is error l-4+{6lz  
} AT*J '37  
/=4 m4  
>.'rN>B+  
String sHeader; c%,@O&o  
H809gm3(Z  
l`"i'P   
for(int i=1;;i++) 5M6`\LyU  
{ B q/<kEgM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YhQ;>Ko  
//Utility.log(in.readLine()); Lso4Z Z;  
sHeader=httpConnection.getHeaderFieldKey(i); 7tbM~+<0  
if(sHeader!=null) zb<YYJ]  
{ Am>^{qh9  
if(sHeader.equals("Content-Length")) -36pkC 6 \  
{ Q[sj/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m][i-|@M  
break; Y'n+,g  
} 9*`(*>S  
} )o4B^kq  
else FZdZGK  
break; UqsJ44QEZ  
} :<Z>?x  
} z _A]mJ  
catch(IOException e){e.printStackTrace ();}  Y7q=]  
catch(Exception e){e.printStackTrace ();} Eu;f~ V  
kF,_o/Jc  
c-s A?q#|  
Utility.log(nFileLength); 6sE%]u<V  
SLGo/I*  
]|6)'L&]*s  
return nFileLength; <,:p?36  
} )7`2FLG  
,\".|m1o.  
<4{Jm8zJ  
//保存下载信息(文件指针位置) aFfd!a" n  
private void write_nPos() a%FM)/oI|T  
{ vZ0K1UTEXY  
try{ V1h&{D\"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); L'A>IBrz  
output.writeInt(nStartPos.length); q`u^ sc  
for(int i=0;i<nStartPos.length;i++) 0 UbY0sYo  
{ "bhF`,V  
// output.writeLong(nPos); ?q lpi(  
output.writeLong(fileSplitterFetch.nStartPos); ;1gWz  
output.writeLong(fileSplitterFetch.nEndPos); [p:mja.6y  
} vGIe"$hNh  
output.close(); A ,$CYLj+  
} m,3H]  
catch(IOException e){e.printStackTrace ();} D~^P}_e.  
catch(Exception e){e.printStackTrace ();} *IGCFZbp41  
} ' 5F3,/r  
t5M"M{V  
@,\J\ rb  
//读取保存的下载信息(文件指针位置) OZ SM2~  
private void read_nPos() 1+Z@4;fk  
{ QT<\E`v  
try{ 1*VArr6*6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y' r I1eF  
int nCount = input.readInt(); aS $ J `  
nStartPos = new long[nCount]; ag* 5fBF  
nEndPos = new long[nCount]; ^T< HD  
for(int i=0;i<nStartPos.length;i++) y$Rh$e K  
{ rm5@dM@  
nStartPos = input.readLong(); ~c\iBk  
nEndPos = input.readLong(); 7] }2`^9  
} s~tZN  
input.close(); -TT{4\%s  
} ;i>(r;ZM  
catch(IOException e){e.printStackTrace ();} tso\bxiU  
catch(Exception e){e.printStackTrace ();} #*~3gMI{=  
} zu! #   
<t"KNKI  
`D,mZj/b  
private void processErrorCode(int nErrorCode) v~AD7k2{8  
{ o+% ($p  
System.err.println("Error Code : " + nErrorCode); p`=v$_]?(  
} cGUsao  
>V$ S\"  
zEMZz$Y  
//停止文件下载 :={rPj-nU  
public void siteStop() MD+e!A#o  
{ t^|GcU]  
bStop = true; G]k+0&X  
for(int i=0;i<nStartPos.length;i++) 3[cGSI"+  
fileSplitterFetch.splitterStop();  oHR@*2b  
zS/1v+  
QZ2a1f'G  
} M'sq{K9  
} MY>*F[~ 2  
//负责部分文件的抓取 ,1e\}^  
**FileSplitterFetch.java pzFM#   
*/ 557%^)v  
package NetFox; $X ]t}=  
i~i ?M)  
4sM9~zC5  
import java.io.*; m;oCi }fL  
import java.net.*; ]?*L"()kp  
n h&[e  
HvJ-P#  
public class FileSplitterFetch extends Thread { myqQqVW  
`+]e}*7$f  
=`/GB T$  
String sURL; //File URL FC q&-  
long nStartPos; //File Snippet Start Position g=Bge)  
long nEndPos; //File Snippet End Position X(qs]:  
int nThreadID; //Thread's ID +T8]R7b9  
boolean bDownOver = false; //Downing is over .gs:.X)TG9  
boolean bStop = false; //Stop identical w1:%P36H  
FileAccessI fileAccessI = null; //File Access interface }:1*@7eR  
HzZ.q2Zz%  
jm&PGZ#n=R  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5fuYva >Ik  
{ Xp?WoC N  
this.sURL = sURL; A(T=  
this.nStartPos = nStart; gI{56Z  
this.nEndPos = nEnd; a'|/=$  
nThreadID = id; ?, oE_H  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5z@QAQ  
} 3bZ:*6W.6  
>fx/TSql:J  
.s`7n *xz  
public void run() sUN9E4  
{ CW'<Nh  
while(nStartPos < nEndPos && !bStop) Po7oo9d  
{ ^.u J]k0  
3&5AbIZ  
Wf>=^ ~`  
try{ a @i?E0Fr  
URL url = new URL(sURL); Q|tzA10E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (Z#j^}G_l  
httpConnection.setRequestProperty("User-Agent","NetFox"); )@E'yHYO>  
String sProperty = "bytes="+nStartPos+"-"; ~NZ}@J{00_  
httpConnection.setRequestProperty("RANGE",sProperty);  Dac ,yW  
Utility.log(sProperty); n~'cKy )m  
b0h>q$b  
UmOK7SPi  
InputStream input = httpConnection.getInputStream(); #waK^B)<a  
//logResponseHead(httpConnection); :8l#jU `y  
gbu@&   
*ez7Q   
byte[] b = new byte[1024]; Gn>~CoFN  
int nRead; 9B2`FJ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7-2,|(Xg  
{ C)|#z/"  
nStartPos += fileAccessI.write(b,0,nRead); o{xA{ @<  
//if(nThreadID == 1) y0\=F  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >IEc4  
} '[Z.\   
v0,&wdi  
+Q&CIo  
Utility.log("Thread " + nThreadID + " is over!"); m}GEx)Y D  
bDownOver = true; {z*`* O@  
//nPos = fileAccessI.write (b,0,nRead); U'Fc\M5l/l  
} "j%L*J)  
catch(Exception e){e.printStackTrace ();} %nT&  
} [K#pU:lTH  
} c*Q6k<SKR  
8npjQ;%4>  
QIu!o,B  
//打印回应的头信息 %\?Gzc_  
public void logResponseHead(HttpURLConnection con) pb}4{]sI  
{ P(Z\y^S  
for(int i=1;;i++) .tt=\R  
{ #u$ Z/,  
String header=con.getHeaderFieldKey(i); fhbILg  
if(header!=null) T[]kun  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +8|r_z\A5a  
Utility.log(header+" : "+con.getHeaderField(header)); /<it2=  
else H <ugc  
break; V|G[j\]E<  
} g0"KC X  
} r:9H>4m  
tqT-9sEXX.  
2~q(?wY  
public void splitterStop() DY!mq91  
{ kH>^3( Q\  
bStop = true; &$hT27A>k  
} k ks ?S',  
2-.%WhE/  
2mVLR;s{_  
} z{dn   
>W?7a:#,  
qD/FxR-!  
/* qr[+^*Ha  
**FileAccess.java N6*v!M+  
*//文件访问(定位,写) *'h vYl/?>  
package NetFox; )uIH onXU  
import java.io.*; z]F4Z'(e.  
3+| {O  
H-Z1i  
public class FileAccessI implements Serializable{ qvhol  
_I}rQfPJ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?{M!syD<  
RandomAccessFile oSavedFile; /"%QIy'{  
long nPos; 60St99@O  
A`qb5LLJ)  
$>mTPNF  
public FileAccessI() throws IOException U?:<clh  
{ jboQ)NxT!,  
this("",0); H<6/i@ly  
} $S0eERg a  
>4}2~;  
qg;f h]j%  
public FileAccessI(String sName,long nPos) throws IOException h f1f  
{ |.zotEh  
oSavedFile = new RandomAccessFile(sName,"rw"); dQ4K^u  
this.nPos = nPos; X@ Gm:6  
oSavedFile.seek(nPos); d.3O1TXK  
} #815h,nP+  
=7c1l77z  
n|oAfJUk,  
public synchronized int write(byte[] b,int nStart,int nLen) Eb<iR)e H=  
{ $N#f)8v  
int n = -1; ]'UO]i/  
try{ F" -w  
oSavedFile.write(b,nStart,nLen); =*YK6  
n = nLen; |ei?s1)  
} 0Up@+R2  
catch(IOException e) 5M{ DJ/q  
{  Y@S?0  
e.printStackTrace (); <4W"ne28  
} '`Smg3T!~S  
y^gazr"  
A2b C5lA  
return n; "kKIVlC  
} ^#R-_I  
u|=G#y;3  
r'p;Nj.  
}  kQ$Q}3f  
|*N.SS  
%3i/PIN  
/* Es kh=xA {  
**SiteInfoBean.java $;_'5`xs  
*/ 'r%`(Z{~  
package NetFox; ,XW6W&vR;  
.e2u)YqA  
<v"C`cga  
public class SiteInfoBean { !b*lL#s,Y  
I~qS6#%r  
-uiZp !  
private String sSiteURL; //Site's URL _VR Sdr5  
private String sFilePath; //Saved File's Path #Xri%&~  
private String sFileName; //Saved File's Name M%:ACLYP  
private int nSplitter; //Count of Splited Downloading File cW,wN~  
4T6dju  
 `-4c}T  
public SiteInfoBean() uG3t%CmN  
{//nSplitter的缺省值为5 Z\xR+3  
//default value of nSplitter is 5 KMznl=LF  
this("","","",5); !xMyk>%2  
} !wvP 24"y  
6Pl$DSu  
Mno4z/4{A  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K(Otgp+zb  
{ <!&nyuSz  
sSiteURL= sURL; r M'snW)  
sFilePath = sPath; J']1^"_'  
sFileName = sName; HPp Kti7g  
this.nSplitter = nSpiltter; f6^H Q1SSt  
c3!d4mC:  
.0#?u1gXsX  
} Yv9(8  
Fg Qd7p  
*gu~7&yoP  
public String getSSiteURL() UBi0 /  
{ j; 1X-  
return sSiteURL; Eti;(>"@  
} ,;H)CUe1"  
GKtG#jZ&  
 {k}S!T  
public void setSSiteURL(String value) RMmDcvM"k  
{ +QuaQ% lA  
sSiteURL = value; \Q?r+VZ  
} r.[!n)*  
ed2QGTgR  
S!2M?}LU  
public String getSFilePath() [$]vi`c2  
{ 1'R]An BV  
return sFilePath; F%lP<4Vx  
} mE%H5&VSI  
7 \!t/<  
8"LvkN/v^  
public void setSFilePath(String value) nv*q N\i'  
{ F.?^ko9d  
sFilePath = value; 5pI2G  
} 7z)Hq./3@  
41^+T<+  
5K;jW  
public String getSFileName() c# U!Q7J  
{ yK_$6EtNKj  
return sFileName; +S5"4<  
} \e T0d<  
8{8J(~  
ux& WN ,  
public void setSFileName(String value) 0[7\p\Q  
{ ^0R.'XL  
sFileName = value; /G9wW+1  
} e]'ui<`  
7MZBU~,r  
d0"Hu^]  
public int getNSplitter() yJ c#y   
{ .EM0R\q  
return nSplitter; C,P>7  
} >Olg lUzA  
u K6R+a  
4%LGP h  
public void setNSplitter(int nCount) B<u6Z!Pp2  
{ o|*ao2a  
nSplitter = nCount; X+z!?W*a  
} F"1)y>2k  
} zt/b S/  
s {p-cV  
l E=(6Q  
/* 7xTgG!>v  
**Utility.java 5I`j'j  
*/ )y4bb^;z  
package NetFox; l=ehoyER  
gHpA@jdC*  
VNBf2Va  
public class Utility { *pK bMG#  
{}kE=L5  
kU{+@MA;  
public Utility() {AUhF}O  
{ <E/4/ ANN  
AiKja>Fl<  
KX D&FDkF  
} 'APtY;x^{  
R?MRRq  
//线程睡眠 h\| ~Q.kG  
public static void sleep(int nSecond) %Xc50n2Z  
{ tIn dve  
try{ `G7LM55  
Thread.sleep(nSecond); sA$x2[*O  
} {w:*t)@j  
catch(Exception e) )r2$!(NQ  
{ (#I$4Px{  
e.printStackTrace (); ere h!  
} j3>0oe!  
} `#@#e Z  
-' :;0  
//日志 (=&z:-52V  
public static void log(String sMsg) O?\UPNb:K  
{ 1g_p`(  
System.err.println(sMsg); 7Z%EXDm4/c  
} DBTeV-G9~R  
<14,xYpE  
TwPp Z@  
public static void log(int sMsg) 9dS<^E(ZF  
{ c{.y9P6  
System.err.println(sMsg); , e^&,5b  
} )M3} 6^s]  
} +vf~s^  
^.3(o{g  
`U4e]Qh/+  
/* [A jY ~  
**TestMethod.java +az=EF  
*/ e^!>W %.7Z  
package NetFox; <Wr n/%tL  
Y@(izC&h  
\d-H+t]  
public class TestMethod { =;L44.,g  
ZNfQM&<d  
wWYo\WH'  
public TestMethod() ]g] ]\hS  
{ ///xx/weblogic60b2_win.exe mETGYkPUa  
try{ ol3].0Vc]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !)r1zSY"g  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #'y4UN  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2I[(UMI$7  
fileFetch.start(); "!S7D >2y#  
}  E\5Cf2Ox  
catch(Exception e){e.printStackTrace ();} Z Jgy!)1n  
O[Yc-4  
m'n<.1;1{j  
} -3GlpC22  
Cfr2 ~w  
`g}po%k  
public static void main(String[] args) W?H-Ng3E  
{ Hb&C;lk  
new TestMethod(); %/n#{;c#  
} SX)o0v+  
} 0n/+X[%Ti  
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