http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Rb:?%\=
} knV*,
for(int i=0;i<nEndPos.length-1;i++) oVbs^sbRH
{ A(`Mwh+
nEndPos = nStartPos[i+1]; #X$s5H
} ls9Y?
nEndPos[nEndPos.length-1] = nFileLength; y<R5}F
} Da6l=M
} #FRm<9/j
B]gyj
W)
//启动子线程 X#ha*u~U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7AGUi+!ICl
for(int i=0;i<nStartPos.length;i++) wEI? 9
{ bvhV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !e |Bi{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |<oqT+?i
nStartPos,nEndPos,i); x.|sCqx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c0&!S-4M
fileSplitterFetch.start(); d>zC[]1
} ""N~##)8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0/7.RpX,.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u`(yT<>H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $*_79F2zN
nEndPos = " + nFileLength); Ks(l :oUB
// fileSplitterFetch[nPos.length-1].start(); gy|o#&e]%
s)-bOZi
7u:kR;wk
//等待子线程结束 0xCe6{86
//int count = 0; tr/.pw6
//是否结束while循环 ?GLCd7TP
boolean breakWhile = false; ph!h8@e
3tUn?;9B
5K$<Ad4$b
while(!bStop) <W7WlT
{ Uy)pEEu
write_nPos(); (47la$CR
Utility.sleep(500); jMS>B)'TO
breakWhile = true; ('dbMH\O
Tl]yl$
w6Mv%ZO_
for(int i=0;i<nStartPos.length;i++) TMsCl6dB
{ G6x'Myg I
if(!fileSplitterFetch.bDownOver) itiSZL,
{ |_+l D|'
breakWhile = false; :1gpbfW
break; #a tL2(wJ
} )_o^d>$da
} 4N7|LxNNl_
if(breakWhile) ;}ThBb3
break; z" ?WT$
]EQ*!
o:4#AkS
//count++; _E6N*ORV
//if(count>4) zq?xY`E
// siteStop(); 8$X3J[_j
} /?TR_>
;AL:VU
Q~' \oWz
System.err.println("文件下载结束！"); 2!b##`UjA7
} `Nz`5}8.?
catch(Exception e){e.printStackTrace ();} .XkVdaX
} 4mX?PKvbn
I};*O6D`
QJjk#*?,|
//获得文件长度 "d}ey=$h4
public long getFileSize() Co=Bq{GY
{ u'DpZ
int nFileLength = -1; 8=0I4\
try{ :LdPqFXj
URL url = new URL(siteInfoBean.getSSiteURL()); c"1Z,M;G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x1E;dbOZ
httpConnection.setRequestProperty("User-Agent","NetFox"); 0XqxW\8_l
pNmWBp|ER
Xi\c>eALO
int responseCode=httpConnection.getResponseCode(); =WZ@{z9J
if(responseCode>=400) n:1Ijh 1
{ e VQ-?DK
processErrorCode(responseCode); }*qj,8-9
return -2; //-2 represent access is error pDvznpQ
} AA=eWg
Y"m(hs$
91q
String sHeader; HGd.meQ
0plX"NU
F>X<=YO0
for(int i=1;;i++) kh#fUAt
{ fl2XI=[v4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y ZuA"l Y
//Utility.log(in.readLine()); N|Xm{@C
sHeader=httpConnection.getHeaderFieldKey(i); H5:f&m
if(sHeader!=null) k6o8'6wN
{ SQx&4R.
if(sHeader.equals("Content-Length")) "Y- WY,H
{ qn |~YXn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cKoW5e|u
break; @tD (<*f+
} 5nsoWqnE8
} >&7^yXS
else ?`O^;f
break; S QGYH
} Un T\6u
} r=54@`O!
catch(IOException e){e.printStackTrace ();} SR?(z
catch(Exception e){e.printStackTrace ();} %&V%=-O_7
S)4p'cUwq
HTvUt*U1
Utility.log(nFileLength); _)~VKA]""
?~yJ7~3TS<
5wl;fL~e
return nFileLength; *-Vr=e<8
} %yk_(3a
o[+t}hC[
wArfnB&
//保存下载信息（文件指针位置） 6f ?,v5
private void write_nPos() .sFN[>)
{ IvI..#EzG
try{ 4fjwC,,
output = new DataOutputStream(new FileOutputStream(tmpFile)); X:g#&e_
output.writeInt(nStartPos.length); 'V&Uh]>
for(int i=0;i<nStartPos.length;i++) x',6VTz^
{ &`tAQN*Z
// output.writeLong(nPos); 4udj"-V
output.writeLong(fileSplitterFetch.nStartPos); S'hUh'PZ
output.writeLong(fileSplitterFetch.nEndPos); *yjnC
} 0'YP9-C3
output.close(); n5^57[(
} ~<s =yjTu+
catch(IOException e){e.printStackTrace ();} oDi+\0
catch(Exception e){e.printStackTrace ();} Qh-:P`CN
} WY!4^<|w"
f#w u~*c
Z,Us<du
//读取保存的下载信息（文件指针位置） WjM7s]ZRv
private void read_nPos() (+/d*4
{ NuD|%Ebs
try{ MxKTKBxQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]yZ%wU9!
int nCount = input.readInt(); *)6\V}`
nStartPos = new long[nCount]; ;^E_BJm
nEndPos = new long[nCount]; pIYXYQ=Z
for(int i=0;i<nStartPos.length;i++) .uxM&|0H
{ aJA(UN45
nStartPos = input.readLong(); R<{Vgy
nEndPos = input.readLong(); ;z N1Qb
} +{I" e,Nk
input.close(); %%>nM'4<
} $AE5n>ZD$
catch(IOException e){e.printStackTrace ();} b(Tvc
catch(Exception e){e.printStackTrace ();} (j??
} M6Np!0G
e"NP]_vh,
#Nco|v
private void processErrorCode(int nErrorCode) C"_ Roir?
{ h0g?=hJq
System.err.println("Error Code : " + nErrorCode); /S1/ZI
} Qx8(w"k*
CS(2bj^6D
p:W]
//停止文件下载 .jk A'i@
public void siteStop() ;+6><O!G
{ &);P|v`8
bStop = true; kV4Oq.E
for(int i=0;i<nStartPos.length;i++) 3JBXGT0gJ
fileSplitterFetch.splitterStop(); 6ST(=X_C
jY]51B
Gsb^gd
} N)R5#JX
} *L$_80
//负责部分文件的抓取 fFr9]
**FileSplitterFetch.java k{N!}%*2
*/ NX.5u8Pf
package NetFox; .8!\6=iJB
v:yU+s|kN
A1,q3<<D%
import java.io.*; 0BhcXHt
import java.net.*; %DXBl:!Y`
A8Fe@$<#8
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public class FileSplitterFetch extends Thread { HK~SD:d
BI%XF 9{
#u8#< ,w
String sURL; //File URL 9q_{_%G%
long nStartPos; //File Snippet Start Position =W:=}ODD
long nEndPos; //File Snippet End Position ?6`B;_m
int nThreadID; //Thread's ID kROIVO1|`
boolean bDownOver = false; //Downing is over mTxqcQc:7
boolean bStop = false; //Stop identical N!3Tg564j
FileAccessI fileAccessI = null; //File Access interface z8JW iRn
F@f4-NR>
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bdb}4X rL
{ JcmJq fR
this.sURL = sURL; >V27#L2:J
this.nStartPos = nStart; NjOUe?BQ
this.nEndPos = nEnd; QSY>8P
nThreadID = id; yV\%K6d|3&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @*Ry`)T
} HdB>CVuh
4\ Xaou2V[
Z/ jmi
public void run() 5:f!EMb
{ Zp~yemERr
while(nStartPos < nEndPos && !bStop) 'g,h
{ L-D4>+
rlY0UA,
_OuNX.yrG
try{ 86Q3d%;-yo
URL url = new URL(sURL); aXJ/"k #Tl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e7xBi!I)~
httpConnection.setRequestProperty("User-Agent","NetFox"); N\g=9o|Q
String sProperty = "bytes="+nStartPos+"-"; !uW*~u
httpConnection.setRequestProperty("RANGE",sProperty); |yeQz
Utility.log(sProperty); Dn 0L%?_
6Uk+a=Ar
"}*D,[C5e
InputStream input = httpConnection.getInputStream(); /u4RZ|&as
//logResponseHead(httpConnection); 'A7!@hVy
hoqZb<:
9>S)*lU&s
byte[] b = new byte[1024]; CMW4Zqau*
int nRead; ~. vridH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yT@Aj;X0v
{ QTi@yT:
nStartPos += fileAccessI.write(b,0,nRead); EOrui:.B)
//if(nThreadID == 1) rtJER?A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y|fD)zG_
} w_Slg&S
)0exGx+:
-|#{V.G3'
Utility.log("Thread " + nThreadID + " is over!"); v-3VzAd=*&
bDownOver = true; K_)~&Cu*'
//nPos = fileAccessI.write (b,0,nRead); qsep9z.
} VRQ`-#
catch(Exception e){e.printStackTrace ();} c.IUqin
} znsQ/[
} w8:[w
%%s)D4sW
9efey? z
//打印回应的头信息 S9Yzvq!(
public void logResponseHead(HttpURLConnection con) 3d6z_Yd:
{ Gc`PO
for(int i=1;;i++) H@1'El\9
{ $kTm"I
String header=con.getHeaderFieldKey(i); x:MwM?
if(header!=null) s"=TM$Vb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8c)GUx
Utility.log(header+" : "+con.getHeaderField(header)); Q/4-7
else t[`LG)
break; {S{%KkAV
} rzAf {2
} m1pA]}Y/5o
@-dGZ5
9m)$^U>oz
public void splitterStop() Hp=BnN
{ -a)1L'R
bStop = true; A r]*?:4y[
} KSchgon0V
qKfUm:7Q_
h$'6."I
} %@Gy<t,
zX_F+"]THt
spfW)v/T!
/* metn&
**FileAccess.java vYV!8o.I
*//文件访问(定位，写) uAA2G\3
package NetFox; @@oJ@;
import java.io.*; x*vD^1"'P
$UH:r
DH?n~qKpC
public class FileAccessI implements Serializable{ &6vaLx
nKm# kb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7?whxi Qs
RandomAccessFile oSavedFile; 5VTVx1P[8
long nPos; a -Pz<*
Ljm`KE\Q;t
)\Q(=:
public FileAccessI() throws IOException Pb'(Y
{ x;7l>uR
this("",0); ck{S
} }?,?2U,8:
Q^f{H.
xkDK5&V
public FileAccessI(String sName,long nPos) throws IOException \PxT47[@e
{ N=\zx^w,
oSavedFile = new RandomAccessFile(sName,"rw"); _s5^\~ao
this.nPos = nPos; H}kZ;8
oSavedFile.seek(nPos); (s;W>,~q
} U~][ ph
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d78 [(;
public synchronized int write(byte[] b,int nStart,int nLen) ?-)!dl%N
{ k 3m_L-
int n = -1; [=(8yUV'G
try{ l9f_NJHo
oSavedFile.write(b,nStart,nLen); ~-zIB=TyK
n = nLen; ,N(Yjq"R
} e El)wZ,A
catch(IOException e) $,~Ily7w
{ ;-VZVp}Y
e.printStackTrace (); r"2lcNE
} X=#us7W}
_ACN
&NBH'Rt
return n; BEaF-*?A
} @??3d9I
ar<8wq<4G
CKn2ZL
} _dm0*T ?
&qS%~h%2
u$R5Q{H_
/* m*]`/:/X[
**SiteInfoBean.java i=#`7pt%'a
*/ E\!X$
package NetFox; \~*<[.8~
<{cY2cx~3
6 ^3RfF^W
public class SiteInfoBean { o`c+eMwr(
~Tt@v`}
C^"zU>W_
private String sSiteURL; //Site's URL eY :"\c3
private String sFilePath; //Saved File's Path CnB[ImMs(A
private String sFileName; //Saved File's Name h}@wPP{
private int nSplitter; //Count of Splited Downloading File YjDQ`f/
gFp3=s0~
{ze69 h
public SiteInfoBean() a5#G48'X
{//nSplitter的缺省值为5 X\Bl? F
//default value of nSplitter is 5 .hmeP MK
this("","","",5); Ts !g=F
} "6'",
f8lyH'z0 @
$Lj]NtO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <u\Hy0g
{ eP]y\S*P
sSiteURL= sURL; 7.Y;nem:(
sFilePath = sPath; HZAT_
sFileName = sName; 'l^Bb#)"
this.nSplitter = nSpiltter; t?>}0\1
-E|"?
QWOPCoUet
} 7_ix&oVI
z)C}}NH*!@
4uiq'-
public String getSSiteURL() VF2,(f-*
{ IRQtA ZV$
return sSiteURL; i)e6U(H
} ,CyX*k8o
&'/"=lK
}9\_s*
public void setSSiteURL(String value) mvjx &+q
{ nKGQU,C
sSiteURL = value; @ 3=pFYW)
} F[}#7}xjA
`$f`55e
eWDXV-xD
public String getSFilePath() @}4>:\es
{ v,}C~L3
return sFilePath; n0l|7:Mk
} ?sQg{1"Zr
nZB~l=
Ij(<(y{?Q1
public void setSFilePath(String value) i[KXkjr
{ q#3T L<
sFilePath = value; %J1'>nI!q
} # QwX|x{
m[=SCH-;
W\>O$IX^e
public String getSFileName() 5Lc@=,/0
{ H"/JR
return sFileName; aaU4Jl?L
} N%f"W&ci
#-YbZ
?-c|c_|$
public void setSFileName(String value) HjK8y@j
{ q+9^rQ
sFileName = value; 68?&`/t
} FBl,Mky
X>7Pqn'
b<y*:(:
public int getNSplitter() 7=N%$]DKZ
{ $EY[CA E
return nSplitter; 0\!Bh^++1
} %BC%fVdP
="]r{
N>3{!K>/Y:
public void setNSplitter(int nCount) 3Y#
{ Q(<A Yu
nSplitter = nCount; *66EkCj
} E&J<qTH9
} kI`HD
6xx.Z3v
&5K3AL
/* m)66g]F+
**Utility.java ^ q ba<#e
*/ ?&0CEfa?
package NetFox; H%m^8yW1
gtH^'vFZ
8#$HKWUK
public class Utility { CX/[L)|Ru
EB&hgz&_
4'D^>z!c
public Utility() qWK}
{ >AV9 K
Fb<'L5}i
^kK")+K
} S".|j$
xb[yy}>"L
//线程睡眠 ?W ^`Fa)]o
public static void sleep(int nSecond) @;9KP6d
{ NUiv"tAY
try{ r^.9 |YM5
Thread.sleep(nSecond); o]p$ w[5
} o!h::j0,~
catch(Exception e) w$$pTk|&n
{ "d/54PKWx
e.printStackTrace (); "T /$K
} y+BiaD!U
} 9*j"@Rm
)X#$G?|Hn
//日志 uq6>K/~D
public static void log(String sMsg) '`}D+IQ(j
{ sifjmNP
System.err.println(sMsg); &56\@t^
} fR;[??NH
:Hitx
xs6!NY
public static void log(int sMsg) S9:ij1
{ y46sL~HRv
System.err.println(sMsg); "?aE3$/
} W{JR%Sq$
} |LIcq0Z
umPN=0u6
nUq@`G
/* T^8`ji
**TestMethod.java 68~]_r.a
*/ 0@'-g^PS
package NetFox; # .&t'"u
9_*3xu<7i
uuHs)
public class TestMethod { *W |
Q.4+"JoG
{3os9r,
public TestMethod() $!'Vn)Z7
{ ///xx/weblogic60b2_win.exe G|&$/]~
try{ %j0c|u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C.=%8|Zy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }rVLWt
SiteFileFetch fileFetch = new SiteFileFetch(bean); N["M "s(N
fileFetch.start(); J|V*g]#kP
} :ldI1*@i<
catch(Exception e){e.printStackTrace ();} 3KD:JKn^
sFfargl
]$)};8;7W
} 1iqgTi>
vEt=enQ
aQWg?,Ju6
public static void main(String[] args) 5#_GuL%
{ %MtaWZ
new TestMethod(); :q1j?0{2N
} !k'E
} *Q [%r
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