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)); d}RU-uiW
} #mIgk'kW<
for(int i=0;i<nEndPos.length-1;i++) #EG W76 f
{ JXx[e
nEndPos = nStartPos[i+1]; Mb!b0
} 3_DwqZ 'O
nEndPos[nEndPos.length-1] = nFileLength; 8O[br@h:5
} H=/;
} #&k`-@b5|
e/7rr~"|
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//启动子线程 pZ`^0#Fo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w@![rH6~F
for(int i=0;i<nStartPos.length;i++) `4SwdW n
{ n 3eLIA{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~=P#7l\o1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <r>1W~bp.q
nStartPos,nEndPos,i); \CU-a`n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C vOH*K'
fileSplitterFetch.start(); >g>L>{
} T1-.+&<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =(==aP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }5Zmc6S{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kTW[)
nEndPos = " + nFileLength); 1 $m[#3
// fileSplitterFetch[nPos.length-1].start(); +L\Dh.Ir
'bQjJRq!
67tB8X
//等待子线程结束 kC_Kb&Q0
//int count = 0; 7&hhKEA
//是否结束while循环 wbpz,
boolean breakWhile = false; W>_K+:t
9#>t% IF~
MaS-*;BY,
while(!bStop) (y^svXU}a
{ SG4)kQ
write_nPos(); ^XgBkC~
Utility.sleep(500); gcA,u)z}R
breakWhile = true; "d; T1
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{3* Ne /
for(int i=0;i<nStartPos.length;i++) r`\6+Ntb.
{ <WiyM[ep
if(!fileSplitterFetch.bDownOver) D7lRZb
{ TWeup6k
breakWhile = false; ,k9xI<i
break; O>@ChQF
} \Dx;AKs
} y$K[ArqX
if(breakWhile) gWIb"l
break; Im!fZg
O<`N0
}~#Tsv
//count++; 6no&2a|D
//if(count>4) ~LF/wx>
// siteStop(); BhzcimC)
} LOEiV
~]Weyb[N
["H2H rI2
System.err.println("文件下载结束！"); )i^S:2
} adn2&7H
catch(Exception e){e.printStackTrace ();} `'E(L&
} zHX7%x,Cq
h]vuBHJ}
1>=]lMW
//获得文件长度 mVd%sWD
public long getFileSize() vnx+1T
{ M\A6;dz'
int nFileLength = -1; `]I p`_{
try{ 2{xf{)hO?
URL url = new URL(siteInfoBean.getSSiteURL()); ?~3Pydrb#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^2`*1el
httpConnection.setRequestProperty("User-Agent","NetFox"); v;nnr0;
|/X+2K}3
C <d]0)
int responseCode=httpConnection.getResponseCode(); [{q])P;
if(responseCode>=400) tiPZ.a~k
{ P r2WF~NuO
processErrorCode(responseCode); Ou]!@s
return -2; //-2 represent access is error Q"s]<MtdS
} `sLD>@m
$}t;c62
&9ERlZ(A
String sHeader; BC)1FxsGf
9>6?tb"f*H
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for(int i=1;;i++) aeE~[m
{ i<M F8$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #2dH2k\F
//Utility.log(in.readLine()); .k"unclT0
sHeader=httpConnection.getHeaderFieldKey(i); 6(/*E=bOKV
if(sHeader!=null) K*P:FCz
{ fD*jzj7o,
if(sHeader.equals("Content-Length")) gn:&akg
{ P>hR${KE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E/hO0Ox6
break; X- j@#Qb
} Z_4|L+i<{
} avY<~-44B
else .naSK`J,`
break; 7 &iav2q
} J|u_45<
} /],9N
catch(IOException e){e.printStackTrace ();} +yxL}=4s
catch(Exception e){e.printStackTrace ();} +W"DN5UV
Tq,dlDDOR
-#Jp@6'k%
Utility.log(nFileLength); lvH} 8lJ
'F^1)Ga$
=C- b#4Q
return nFileLength; E/2_@&U:}
} `Krk<G
[JEf P/n|.
AEd9H +I
//保存下载信息（文件指针位置） 9z+ZFIf7d
private void write_nPos() nP0rg
{ +t8#rT ^B
try{ #s{EIj~YR_
output = new DataOutputStream(new FileOutputStream(tmpFile)); |`pDOd
output.writeInt(nStartPos.length); O jH"qi
for(int i=0;i<nStartPos.length;i++) dN@C)5pm5`
{ UHS"{%
// output.writeLong(nPos); {$I1(DYN
output.writeLong(fileSplitterFetch.nStartPos); L=gG23U&
output.writeLong(fileSplitterFetch.nEndPos); @CS%=tE}U
} ! u9LZ
output.close(); ;( (|0Xa
} V6&6I
catch(IOException e){e.printStackTrace ();} J;N\q
catch(Exception e){e.printStackTrace ();} ~!P&LZ
} |#sY(1
JvF0s}#4
= Atyy
//读取保存的下载信息（文件指针位置） _FkH;MGWS
private void read_nPos() IM_SZs
{ pp+z5
try{ _adW>-wQ!d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $mxl&Qr>Q;
int nCount = input.readInt(); $ncP#6
nStartPos = new long[nCount]; _FCg5F2U
nEndPos = new long[nCount]; ~En]sj
for(int i=0;i<nStartPos.length;i++) MaZVGrcC
{ hVNT
nStartPos = input.readLong(); ,MUgww!.
nEndPos = input.readLong(); lL,0IfC,
} 4'y@ne}g!
input.close(); 1sq1{|NW~
} #&Rx?V
catch(IOException e){e.printStackTrace ();} N7!(4|14
catch(Exception e){e.printStackTrace ();} "(iQ-g Mm
} drJUfsxV
usw(]CnH
!O4)YM
private void processErrorCode(int nErrorCode) sY* qf=
{ h#Z~x
System.err.println("Error Code : " + nErrorCode); B.}j1Bb
} zd=N.
x,c\q$8yH
_opB,,G
//停止文件下载 2BO"mc<#$
public void siteStop() #Eqx Eo;
{ XdE|7=+s
bStop = true; s0'6r$xj
for(int i=0;i<nStartPos.length;i++) SP4(yJy&
fileSplitterFetch.splitterStop(); t\O#5mo
SmV}Wf
*t`=1Ioj
} k/i&e~! \
} Ej<`HbJ'Q
//负责部分文件的抓取 .SDE6nvbW
**FileSplitterFetch.java {6mFI1;q
*/ >gDKkeLD
package NetFox; dB8 e
@&GY5<&b
#e[igxwi
import java.io.*; 91UC>]}H
import java.net.*; $\L=RU!c}
j07b!j:"\}
} a!HbH
public class FileSplitterFetch extends Thread { ->W rBO
L$?YbQo7
0y%s\,PsT
String sURL; //File URL S~B{G T\M
long nStartPos; //File Snippet Start Position Zbf~E {
long nEndPos; //File Snippet End Position |AS9^w
int nThreadID; //Thread's ID /5~j"| U'
boolean bDownOver = false; //Downing is over 10tt':
boolean bStop = false; //Stop identical T/tCX[}
FileAccessI fileAccessI = null; //File Access interface of>H&G)@
A`V:r2hnb
L(}/W~En
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4 ;^
{ ",]A.,
this.sURL = sURL; j|VX6U
this.nStartPos = nStart; !Hj 7|5
this.nEndPos = nEnd; B %
nThreadID = id; AIw~@*T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OKnpG*)u=g
} 2 ;Q|h$n
Hi&bNM>?O
54Vb[;`Kkb
public void run() !3\( d{
{ ySHio;g9
while(nStartPos < nEndPos && !bStop) q)N^
{ vAtR\Vh
Er|j\(jM
Q@rlqWgU ~
try{ eY_BECJ+OO
URL url = new URL(sURL); >[g.8'hI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,<;.'r
httpConnection.setRequestProperty("User-Agent","NetFox"); Ll`nO;h
String sProperty = "bytes="+nStartPos+"-"; ew,g'$drD
httpConnection.setRequestProperty("RANGE",sProperty); T!|-dYYI
Utility.log(sProperty); P%ZU+ET
W7w*VD|
_3{8Zg
InputStream input = httpConnection.getInputStream(); 3m"9q
//logResponseHead(httpConnection); /KhY,G'Z
k>#-NPU$
u+ 8wBb5!
byte[] b = new byte[1024]; 5yf`3vV|3@
int nRead; Lt{&v^y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uf`/-jY
{ ki8Jl}dr
nStartPos += fileAccessI.write(b,0,nRead); /p)y!5e
//if(nThreadID == 1) 9w-;d=(Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MX7$f (Hy
} O>IG7Ujl
"Jg* /F
d V3R)
Utility.log("Thread " + nThreadID + " is over!"); _!k\~4U
bDownOver = true; )_K:A(V>
//nPos = fileAccessI.write (b,0,nRead); DS7Pioa86
} J74kK#uF=
catch(Exception e){e.printStackTrace ();} R".*dC,0'B
} [k=LX+w@
} Kk>va->R
#^w8Y'{?
=!=DISPo
//打印回应的头信息 QPW+L*2
public void logResponseHead(HttpURLConnection con) sbV_h;<
{ g8]$BhRIfr
for(int i=1;;i++) BWzo|isv
{ GX N:=
String header=con.getHeaderFieldKey(i); Z )X(
if(header!=null) >n5Kz]]%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l'?(4N
Utility.log(header+" : "+con.getHeaderField(header)); ,1il&
else )Hqn
break; 1+Bj` ACP
} YGZa##i
} !uhh_3RH
+`TwBN,kp-
p9eTrFDy?
public void splitterStop() nu6v@<<F>
{ [-1Yyy1}
bStop = true; ]F4|@+\9
} Jg@eGs\*
ORt)sn&~d
U-#vssJhk
} ]u%Y8kBe
FZfhiIf
^Fwdi#g
/* `12Y2W 9
**FileAccess.java D`PA@t
*//文件访问(定位，写) LP}j0)n
package NetFox; RYM[{]4b5F
import java.io.*; /[|A(,N}{
?aU-Y_pMe
;z9U_
public class FileAccessI implements Serializable{ %D[6;PT
w=ZK=@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5-"aK~@+
RandomAccessFile oSavedFile; Bacmrf
long nPos; n;r W
HG)h,&nc-
m!:sDQn{3
public FileAccessI() throws IOException 03 ;L
{ 3EyVoS6D
this("",0); BSg3
} :BUr8%l
ExSy/^4f
9<"l!noy
public FileAccessI(String sName,long nPos) throws IOException 7/FF}d
{ 8o,"G}Hjk
oSavedFile = new RandomAccessFile(sName,"rw"); CoM?cS S
this.nPos = nPos; 9j$J}=y
oSavedFile.seek(nPos); s5oU
} Yu|L6#[E
Y NGS"3F
D=~3N
public synchronized int write(byte[] b,int nStart,int nLen) {Pe+d3Eoo
{ bYy7Ul6]
int n = -1; p;LF-R
try{ :JzJ(q/
oSavedFile.write(b,nStart,nLen); ''B}^yKEW
n = nLen; @;{iCVW
} Ryi%}!
catch(IOException e) ,/..f!bp
{ sT>l ?L
e.printStackTrace (); v;IuB
} Ai5D[ykX
s@|TQ9e |j
HeM-
return n; c4L++ u#
} {(^%2dk83C
|3 v+&eVi
3NgyF[c
} +'9eo%3O
6g'+1%O
]}BT'fky#
/* t+n+_X
**SiteInfoBean.java .q9i10C
*/ F vHd`
package NetFox; T :X A
>FReGiK$T
q%MLj./?[
public class SiteInfoBean { RU,!F99'1
)5ISkbsxD
usI$
private String sSiteURL; //Site's URL ~)iQbLI
private String sFilePath; //Saved File's Path G!w?\-
private String sFileName; //Saved File's Name ;Y`k-R:E6A
private int nSplitter; //Count of Splited Downloading File X8(WsN
)[5.*g@
f=nVK4DuZ
public SiteInfoBean() ~9dAoILrl
{//nSplitter的缺省值为5 a9TKp$LP`
//default value of nSplitter is 5 go5l<:9
this("","","",5); BY??X=
} n;*W#c
3+iQct[
s F3M= uz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w-?Cg8bq<
{ x-@6U
sSiteURL= sURL; ZVz`-hB
sFilePath = sPath; +zSdP2s
sFileName = sName; ~bLhI
this.nSplitter = nSpiltter; `r.
Mt+ggF.
XnV$}T:?X
} 3ypf_]<
firiYL"=44
VseeU;q
public String getSSiteURL() s@5r}6?M
{ IP l]$j>N
return sSiteURL; u YJL^I8M'
} [7gwJiK
!7aJfs2
Bhw|!Y&%
public void setSSiteURL(String value) ;>B06v
{ Y(P<9m:
sSiteURL = value; T'e p&tNY
} KVCj06}j
gD/% l[
GYNLyd)
public String getSFilePath() ?$AWY\
{ ~[4zm$R^
return sFilePath; g=x1}nm
} {Qj7?}xW
=E' .T0v
hS+R/7
public void setSFilePath(String value) V2_I=]p_
{ VNWa3`w
sFilePath = value; b0R{cj=<[
} E>O1dPZcM
nwPU{4#l<
q.NvwJ
public String getSFileName() ,N`D{H"F
{ M[,G#GO
return sFileName; z+6%Ya&ls
} Z|qUVD5Ic
cp<jwcc!
9aZ^m$tAt
public void setSFileName(String value) }uk]1M2=
{ 6i_dL|c
sFileName = value; ;B@-RfP
} ,]|*~dd>G
xl;0&/7e
c %.vI
public int getNSplitter() \h 1T/_4
{ lT~A~O
return nSplitter; 6pY<,7t0
} Y'v;!11#
y]TNjLpo$
7H5t!yk|9
public void setNSplitter(int nCount) F otHITw[
{ _f@, >l
nSplitter = nCount; D^e7%FX
} :T#"bY
} ;#Pc^Yzc1
DB;Nr3x
61{IXx_
/* F_C_K"[s
**Utility.java *;yn_zg
*/ [*AWCV
package NetFox; /yS/*ET8
!E|k#c9
Wg ?P"
public class Utility { iHL`r1I!
2OQDG7#Kc
B!zqvShF
public Utility() cJ!C=J
{ ,=Fn6'
yCG<qQz
@%sr#YqY
} 1I -LGe[Q
+F3`?6UXz
//线程睡眠 lc2RMu
public static void sleep(int nSecond) JOm6Zc
{ J=C63YB
try{ =FtJa3mHK
Thread.sleep(nSecond); K]Onb{QY
} K JX@?1"
catch(Exception e) e<[0H 8
{ OGqsQ
e.printStackTrace (); ,%%}d9
} v9R"dc]0h
} [#-!&>
=j{r95)|u
//日志 b&1-tYV
public static void log(String sMsg) <m3or
{ c/\$AJV.H
System.err.println(sMsg); #\)tz z
} yL>wCD,L
t=Um@;wh
,Y3wXmG
public static void log(int sMsg) I_h{n{,sr
{ 81<0B@E
System.err.println(sMsg); Z2x%
} hpVu
} Qo;#}%}^^
)Mj $/
';0NWFP
/* J\V.J/
**TestMethod.java 3Ta<7tEM
*/ Cq-#|+zr
package NetFox; .6D9m.Q,
';hTGLq\X
oz- k_9%
public class TestMethod { 9?_ybO~Oq
OnKPD=<
AZTn!hrU
public TestMethod() j |tu|Q
{ ///xx/weblogic60b2_win.exe ^,M&PP6
try{ &G"r>,HU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &RP}w%I1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \1p5$0z
SiteFileFetch fileFetch = new SiteFileFetch(bean); f YuM`O
fileFetch.start(); ^sjL@.'m$N
} j2/3NF5&
catch(Exception e){e.printStackTrace ();} sUP!'Av
@~l?hf
P_w\d/3
} X;?Z_3I:5
7JNy;$]/
Mn=5yU
public static void main(String[] args) KtFxG6a
{ S"z cSkF
new TestMethod(); a}w%k
} khW9n*
} X0.-q%5
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