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)); tzx:*
} r[Zg 2
for(int i=0;i<nEndPos.length-1;i++) ajf_)G5X P
{ oiIt3<BX
nEndPos = nStartPos[i+1]; pb,{$A
} /5Gnb.zN)
nEndPos[nEndPos.length-1] = nFileLength; TG""eC!E
} F Bd+=bx,Z
} h#$_<U
:YkDn~@
WBIQ%XB'
//启动子线程 }])GQ@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .D>A'r8U
for(int i=0;i<nStartPos.length;i++) @ J?-a m>
{ D/+@d:-G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NB~*sP-l&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C.DoXE7
nStartPos,nEndPos,i); Pl`Bd0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s>[vT?
fileSplitterFetch.start(); gDUoc*+h
} BV_a-\Sa=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6%Cna0x:&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @U7U?.p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (7 ]\p
nEndPos = " + nFileLength); arpJiG~JR
// fileSplitterFetch[nPos.length-1].start(); /9t*CEu\
gwkZk-f\p
v=8~ZDY
//等待子线程结束 ,cl"1>lp
//int count = 0; 5VY%o8xXa
//是否结束while循环 z^SN#v$
boolean breakWhile = false; K~9 jin
T`0`]z!~
}K qw\]`
while(!bStop) }b\ipA,~
{ d-_93
write_nPos(); KJ05Zx~uma
Utility.sleep(500); J}93u(T5
breakWhile = true; Z:}2F^6
g tSHy*3]
!E(J ]a
for(int i=0;i<nStartPos.length;i++) [jmAMF<F
{ Y }g6IK}
if(!fileSplitterFetch.bDownOver) f/|a?n2\hm
{ d<^6hF
breakWhile = false; \t7zMp
break; Jg?pW:}R
} Sd/d [
} Vo58Nz:%
if(breakWhile) _j?=&tc
break; 55)ep
]mDsUZf<
LVz%$Cq,0
//count++; kk>0XPk
//if(count>4) M4$4D?
// siteStop(); z8rh*Rfxd
} w{UKoU
1OJD\wc
G5Dji_|
System.err.println("文件下载结束！"); r+WPQ`Ar
} 5la]l
catch(Exception e){e.printStackTrace ();} )SO1P6
} ob()+p.kK
. KSr@Gz
5&7?0h+I
//获得文件长度 5;uX"zG
public long getFileSize() M<me\s)
{ 2QQYXJ^
int nFileLength = -1; - G2M;]Cn
try{ T;vPR,]rz
URL url = new URL(siteInfoBean.getSSiteURL()); ?.'oxW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ri_6wbPp
httpConnection.setRequestProperty("User-Agent","NetFox"); x'PjP1
X0J]6|du.
j~<iTLM
int responseCode=httpConnection.getResponseCode(); 0}3'h#33=
if(responseCode>=400) 7=[O6<+o
{ D +%k1
processErrorCode(responseCode); '/)_{Ly
return -2; //-2 represent access is error k*+ZLrT
} tfU3 6PR
YSUH*i/%
t 1'or
String sHeader; XhkL))FcG
aLo>Yi
[A/+tv
for(int i=1;;i++) !ES#::;z?
{ 761"S@tf$}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4BL,/(W] x
//Utility.log(in.readLine()); u+T, n
sHeader=httpConnection.getHeaderFieldKey(i); ;DWp>jgy
if(sHeader!=null) .0/Z'.c8
{ @G-k]IWi
if(sHeader.equals("Content-Length")) YQd&rkr
{ A>,fG9pR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,,-3p#Pbw
break; "4-Nnm
} m<HjL
} *y@]zNPD
else w%u[~T7OI
break; yxq!.72
} S6:gow(wU
} y#W8] <dS"
catch(IOException e){e.printStackTrace ();} s+t eYL#Zi
catch(Exception e){e.printStackTrace ();} KFrmH
~Q\uP(!D
]$*_2V3VA$
Utility.log(nFileLength); `SbX`a0p2
3W WxpTU
@WE$%dr
return nFileLength; /JYi^rZ
} enepAu-="p
jpS#'h
fxa^SV
//保存下载信息（文件指针位置） <]`2H}*U'
private void write_nPos() aM1JG$+7G
{ |n%N'-el
try{ 4r!40^:2
output = new DataOutputStream(new FileOutputStream(tmpFile)); yXmp]9$
output.writeInt(nStartPos.length); Za?&\
for(int i=0;i<nStartPos.length;i++) +u.L6GcB
{ ps J 1J
// output.writeLong(nPos); lO@Ba;x
output.writeLong(fileSplitterFetch.nStartPos); >QPS0Vx[
output.writeLong(fileSplitterFetch.nEndPos); 0pz X!f1~
} . 2Q/D?a
output.close(); \Ki#"%S
} 3xY]Lqwv
catch(IOException e){e.printStackTrace ();} (9%%^s]uPT
catch(Exception e){e.printStackTrace ();} t0(hc7`
} o%7yhCY
wAPdu y[
] lTfi0}g_
//读取保存的下载信息（文件指针位置） \`x'g)z(i
private void read_nPos() ttRH[[E(
{ S?<Qa;
try{ 5eJd$}Lbc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )2hoO_l:
int nCount = input.readInt(); zD|W3hL2&
nStartPos = new long[nCount]; BW[K/l~"$:
nEndPos = new long[nCount]; wtyu"=
for(int i=0;i<nStartPos.length;i++) XCoOs<O:@
{ .? /J
nStartPos = input.readLong(); i{0_}"B
nEndPos = input.readLong(); omu&:) g
} W=:+f)D
input.close(); 64@s|m*
} c^%k1pae(
catch(IOException e){e.printStackTrace ();} rY.:}D
catch(Exception e){e.printStackTrace ();} ]y e&#
} *WG}K?"/
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fZC,%p
private void processErrorCode(int nErrorCode) ?;Qk!t2U
{ cCs:z
System.err.println("Error Code : " + nErrorCode); .}wir,
} i:72FVo
\8ZNXCP
n66_#X
//停止文件下载 }z#8vE;
public void siteStop() 71InYIed
{ DFMWgBL
bStop = true; ~r3g~MCHS
for(int i=0;i<nStartPos.length;i++) 0Og =H79<
fileSplitterFetch.splitterStop(); Ns_d10rZ.
3IIlAzne;
l(W3|W#P
} ^8)d8?}
} @U5o;X!qU
//负责部分文件的抓取 DQd&:J@?
**FileSplitterFetch.java 5o*x?P!$
*/ \T?O.
package NetFox; J4<*KL~a
[sBD|P;M
l3,|r QD
import java.io.*; ge|}'QKow
import java.net.*; 5h&8!!$[
:Pv{E
NbdaP{{
public class FileSplitterFetch extends Thread { _wMz+<7bY
-c tZ9+LL
}PVB+i M
String sURL; //File URL ;FUd.vg{
long nStartPos; //File Snippet Start Position _F9 c.BH
long nEndPos; //File Snippet End Position J7H1<\=cJb
int nThreadID; //Thread's ID y< 84Gw_
boolean bDownOver = false; //Downing is over PuWF:'w r
boolean bStop = false; //Stop identical #oaX<,
FileAccessI fileAccessI = null; //File Access interface c!c!;(
btOC\bUMfD
y=CemJ[~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]Q+Tm2{
{ Q["}U7j
this.sURL = sURL; <M=K!k
this.nStartPos = nStart; OP@PB|
this.nEndPos = nEnd; |<E%hf
nThreadID = id; 28-@Ga4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "(5M }5D
} yR&E6o.$z
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public void run() MkQSq MU=
{ F~m tE8B:
while(nStartPos < nEndPos && !bStop) 5%9& 7
{ Wl1%BN0>
B=f{`rM)~W
/<@oUv
try{ GB0] |z5
URL url = new URL(sURL); }Vt5].TA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2`; 0y M
httpConnection.setRequestProperty("User-Agent","NetFox"); `Tab'7
String sProperty = "bytes="+nStartPos+"-"; h' 16"j>
httpConnection.setRequestProperty("RANGE",sProperty); ]5^u^
Utility.log(sProperty); QDU^yVa_
PffRV7qU0
hHdC/mR
InputStream input = httpConnection.getInputStream(); 9 eP @}C6
//logResponseHead(httpConnection); B!,})F$x
$]O\Ryf6
UXd\Q''
byte[] b = new byte[1024]; Ji=E 1R
int nRead; zU(U^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q*2ljcb55
{ 3]wV`mD
nStartPos += fileAccessI.write(b,0,nRead); &AW?!rH
//if(nThreadID == 1) 6,k}v:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b.$Gc!g
} wsM5TB
T\OLysc
67d0JQTu
Utility.log("Thread " + nThreadID + " is over!"); ^Xh9:OBF
bDownOver = true; 0%vXPlfnY
//nPos = fileAccessI.write (b,0,nRead); tvP"t{C6,
} KnlVZn[3t
catch(Exception e){e.printStackTrace ();} tvI~?\Ylj
} )5hS;u&b
} 4rv3D@E
D9JT)a
c" yf>0
//打印回应的头信息 "xw2@jGpG
public void logResponseHead(HttpURLConnection con) -BR&b2
{ 2&dtOyxo>
for(int i=1;;i++) 9hcZbM]
{ 0?k/vV4
String header=con.getHeaderFieldKey(i); (ZDRjBth[
if(header!=null) (G:$/fK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Krz[ f
Utility.log(header+" : "+con.getHeaderField(header)); ]e R1 +Nl
else Si!W@Jm
break; jh9^5"vQ
} `XQM)A
} 'H:lR1(,
iz>a0~(K
Aqq%HgY:t
public void splitterStop() G.1pg]P!
{ eo"6 \3z
bStop = true; r'-)@|
} TR|G4l?
3. fIp5g
RytQNwv3
} !\^c9Pg|v
u.R:/H<>~
bNj| GIf
/* "@DCQ
**FileAccess.java &!a[rvtZ+
*//文件访问(定位，写) (q*Za
package NetFox; p\~ lPXK
import java.io.*; + ,0RrD )
pJ1GB
a'rN&*P
public class FileAccessI implements Serializable{ 4, 8gf2
8g^OXZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yD$rls:v<
RandomAccessFile oSavedFile; USfOc
long nPos; OiZPL"Q(K
aV,>y"S
h{VCx#!]
public FileAccessI() throws IOException o0_RU<bWN
{ % =br-c
this("",0); rer=o S
} pu=Q;E_f[
+(QGlRd
qJKD|=_
public FileAccessI(String sName,long nPos) throws IOException 4L(axjMYU
{ 2>_6b>9]
oSavedFile = new RandomAccessFile(sName,"rw"); JIQS'r
this.nPos = nPos; |U>BXX P
oSavedFile.seek(nPos); \|L@
} !Yz~HO,u+
:DCj2"
K3M<%
public synchronized int write(byte[] b,int nStart,int nLen) Z ~:S0HDP
{ ZOi8)Y~
int n = -1; bo4 :|Z
try{ 1BmevEa)
oSavedFile.write(b,nStart,nLen); ,yNPD}@v>
n = nLen; ]4@_KKP
} % Lhpj[C
catch(IOException e) nxA Y]Q
{ >t20GmmN
e.printStackTrace (); ;lB%N t<,
} Y7zg
i-vhX4:bd
9N:Bu'j&/
return n; FAzshR
} `_N8AA
f nX!wN
!vHnMY~AG
} n{6XtIoYq
Ks(+['*S
k3da*vwE
/* @kenv3[Lc
**SiteInfoBean.java .9#4qoM'
*/ T2P0(rEz
package NetFox; q&B'peT
0m(/hK
{OL*E0
public class SiteInfoBean { f<= #WV
J^R))R=
mnzamp
private String sSiteURL; //Site's URL #'^!@+)
private String sFilePath; //Saved File's Path |FHeT*"
private String sFileName; //Saved File's Name [rC-3sGar
private int nSplitter; //Count of Splited Downloading File Ek~Qp9B
"WdGY*r
(\{9W
public SiteInfoBean() E ~<SEA
{//nSplitter的缺省值为5 B.-5$4*s
//default value of nSplitter is 5 BNw^ _j1
this("","","",5); ,A[40SZA
} o7i/~JkTP
PspH[db
!@{_Qt1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OkGg4X|9
{ ^3B{|cqf
sSiteURL= sURL; qL091P\F
sFilePath = sPath; .+t{o[
sFileName = sName; Oh9wBV
this.nSplitter = nSpiltter; 4(o: #9I
~O;!y%
=G]} L<
} R"Nvnpm
=24)`Lyb
[X ]\^
public String getSSiteURL() PwU}<Hrl]
{ TS^(<+'
return sSiteURL; }jBr[S5
} l~!Tnp\M
<?kr"[cQeP
jhjGDF
public void setSSiteURL(String value) W?mn8Y;{`
{ 9:4PJ%R9
sSiteURL = value; *M\Qt_[
} [X0Wfb}{
Ap9CQ h=!
XeX0\L')R
public String getSFilePath() %Js3Y9AL C
{ zuUf:%k}I
return sFilePath; $'btfo4H
} e;~[PYeu
%Ez%pT0TQ#
.",E}3zn
public void setSFilePath(String value) `=Pn{JaD
{ } R!-*Wk
sFilePath = value; hAi50q;z
} fp|!LU
y;<^[
ugcWFB5|
public String getSFileName() SoeL_#+^W
{ 7\@[e, ^9
return sFileName; ^$f}s,09
} 6f,#O8]#5
"]>JtK
>i7zV`eK
public void setSFileName(String value) z #c)Q
{ :$."x '
sFileName = value; zm4Okg)w@
} P9; =O$s
h~{TCK+I
Qc#<RbLL
public int getNSplitter() w^e<p~i!^E
{ 9iGUE
return nSplitter; qFp }+s
} />c F
3Xyu`zS&
+#7e?B
public void setNSplitter(int nCount) ,0O9!^
{ URS6 LM
nSplitter = nCount; AeR3wua
} #8iRWm0*6
} 4^\5]d!
&QFg=
<seb,> :
/* 4%>iIPXi.(
**Utility.java eFS;+?bu
*/ *-"DZ
package NetFox; BS*IrH H
2<53y~Yi%
,pL%,>R5
public class Utility { ':YFm
%_C!3kKv~
FJJ+*3(
public Utility() 7.7P>U
{ N GP}Z4
21i?$ uU
/KGVMBifM
} e<o{3*%p)
[)UL}vAO\q
//线程睡眠 YLs%u=e($
public static void sleep(int nSecond) @H[)U/.
{ s8;/'?K
try{ d Bn/_
Thread.sleep(nSecond); VBV y3fnj
} WgX9k J
catch(Exception e) @%Y$@Qb{
{ j_L1KB*
e.printStackTrace (); 2\Bt~;EIx
} w5zrEk#
} =_~bSEqyRI
8+'9K%'@qX
//日志 W$&{jr-p
public static void log(String sMsg) m/}(dT;
{ 'MZX"t
System.err.println(sMsg); AA$+ayzx9{
} S5B12P
4rkj$
\$;Q3t3
public static void log(int sMsg) nO-1^HUl
{ EG=~0j~
System.err.println(sMsg); 8K(3{\J[V
} S ?v^/F
} 9PpPAF
?O]iX;2vM
D$ >gAv
/* vCPiT2G
**TestMethod.java I eQF+Xz
*/ {;iG}jK
package NetFox; EPY64{
dWg09sx
.6@qU}
public class TestMethod { qTGEi
6" s}<
RsY7F;
public TestMethod() `#X\@?'5
{ ///xx/weblogic60b2_win.exe jK#[r[q{
try{ ;bC163[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4bT21J37
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )\iOwA
SiteFileFetch fileFetch = new SiteFileFetch(bean); sz5&P )X
fileFetch.start(); > @Ux8#
} -ZmccT"8
catch(Exception e){e.printStackTrace ();} O{sb{kk
3Pb]Of#
E"EBj7<s
} (A6-9g>
e``X6=rcG
4h|48</
public static void main(String[] args) |"7^9(
{ QasUgZ
new TestMethod(); N*k`'T
} z[7j`J|Kk
} ;:w?&4
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