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)); {}:ToIp
} OzC\9YeA
for(int i=0;i<nEndPos.length-1;i++) \=>H6x]q
{ 3]?#he
nEndPos = nStartPos[i+1]; %Qk/_ R1
} <V>dM4Mkr
nEndPos[nEndPos.length-1] = nFileLength; UwC=1g U
} _#vrb;.+
} Xy%p"b<
imiR/V>N
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//启动子线程 ^] kF{ o?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O#Wh TDF"
for(int i=0;i<nStartPos.length;i++) i*CZV|t US
{ ?.Pg\ur
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]r_;dYa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vOg#Dqn-
nStartPos,nEndPos,i); ,]T2$?|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <id}<H
fileSplitterFetch.start(); ^eoLAL
} s=[h?kB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,!U=|c"k)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &IlU|4`R%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `Qeg
nEndPos = " + nFileLength); VE8;sGaJ
// fileSplitterFetch[nPos.length-1].start(); 0@AAulRl
*-xU2
;j2vHU#q-
//等待子线程结束 Qyy.IPTP
//int count = 0; kY'T{Sm1^
//是否结束while循环 LiKxq=K
boolean breakWhile = false; `mN4_\]
\rPbK+G.
t'ZWc\
while(!bStop) <I"S#M7-s
{ b:w?PC~O
write_nPos(); Ag@;
Utility.sleep(500); u_rdmyq$x/
breakWhile = true; |2KAo!PI
cp o-.
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for(int i=0;i<nStartPos.length;i++) fNrgdfo
{ NssELMtF!g
if(!fileSplitterFetch.bDownOver) ;D$)P7k6
{ _2N$LLbg
breakWhile = false; D1&A,2wO
break; <\;#jF%V
} o;?/HE%,[
} 85GKymz$P
if(breakWhile) MQ"xOcD*F
break; r7',3V
p ]d]QMu
~9j%Hm0ht
//count++; ?@V[#.
//if(count>4) FHV-BuH5
// siteStop(); ^+g$iM[`f
} jRL<JZ1N
H#ncM~y*
L5,NP5RC
System.err.println("文件下载结束！"); u7=U^}#
} /d%=E
catch(Exception e){e.printStackTrace ();} B7!3-1<k>
} !o$!Frc
aE2.L;Tk?
t]-5 ]oI
//获得文件长度 [p<w._b i
public long getFileSize() ^yOZArc'r
{ F;]%V%F.X
int nFileLength = -1; -a-(r'Qc(
try{ [Jv@J\
URL url = new URL(siteInfoBean.getSSiteURL()); #t+d iR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f%*/cpA)
httpConnection.setRequestProperty("User-Agent","NetFox"); 8]LD]h)B"
Z4\=*ic@
l'eyq}&
int responseCode=httpConnection.getResponseCode(); 6R^^.tCs
if(responseCode>=400) 8-O)Xx}cU
{ LGtIm7
processErrorCode(responseCode); V5rST +
return -2; //-2 represent access is error KY~-;0x
} BT(CM,bp
rOVVL%@QqJ
w`5xrqt@
String sHeader; Ih"XV
cCxBzkH6
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for(int i=1;;i++) ,S!azN=
{ }+sT4'Ah>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Er{>p|n=
//Utility.log(in.readLine()); yNTK .
sHeader=httpConnection.getHeaderFieldKey(i); ej"+:."\e
if(sHeader!=null) 0vw4?>Jf@
{ VTH> o>g
if(sHeader.equals("Content-Length")) >qF CB\(
{ =y-@AU8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $b mLu=9
break; a0#J9O_
} (I./ Uu%
} 1.6:#
else .;N1N^
break; (UxW;
} V=*wKuB
} <Sr
catch(IOException e){e.printStackTrace ();} [)TRTxFb
catch(Exception e){e.printStackTrace ();} r! MWbFw|X
N}t 2Nu-
Ll4g[8
Utility.log(nFileLength); 5bgs*.s
sL$:"=
)<tI!I][j
return nFileLength; 9c("x%nLpB
} l~$+,U&XNe
IqoR7ajA
5wDg'X]>V
//保存下载信息（文件指针位置） sc,vj'r
private void write_nPos() )'+8}T]xQ
{ WA&!;Zq
try{ #NryLE!/
output = new DataOutputStream(new FileOutputStream(tmpFile)); bXNk%W[n
output.writeInt(nStartPos.length); =aTv! 8</
for(int i=0;i<nStartPos.length;i++) 1waTTT?"Ho
{ L}pt)w*V1j
// output.writeLong(nPos); W@I|Q -
output.writeLong(fileSplitterFetch.nStartPos); N <Xq]! K-
output.writeLong(fileSplitterFetch.nEndPos); z.;ez}6%V
} 71t*%
output.close(); q}?4f*WC
} ys kO
catch(IOException e){e.printStackTrace ();} Z'7
catch(Exception e){e.printStackTrace ();} P`cq H(
} WL"^>[Vq
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j=r P:#
//读取保存的下载信息（文件指针位置） @pRlxkvV
private void read_nPos() ][p>Y>:b-
{ ~XmLX)vO/
try{ GVYkJ0,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yz+ZY
int nCount = input.readInt(); rr02pM0
nStartPos = new long[nCount]; M,\:<kNI
nEndPos = new long[nCount]; x5-}h*
for(int i=0;i<nStartPos.length;i++) S;286[oq@
{ Rx=>6,)'
nStartPos = input.readLong(); lUMS;H(
nEndPos = input.readLong(); fUA uqfj[
} 1`qMj0Y_
input.close(); [rV>57`YD
} 4p,EBn9(
catch(IOException e){e.printStackTrace ();} '|8} z4/g
catch(Exception e){e.printStackTrace ();} GE%Z9#E
} P 'od`
hFy;ffs.
DrY:9[LP
private void processErrorCode(int nErrorCode) ]Hefm?9*^
{ j~jV'f.:H
System.err.println("Error Code : " + nErrorCode); =*c7i]@}
} /n{omx
A#J`;5!Sc
lHPd"3HDK
//停止文件下载 f\sQO&
public void siteStop() ]\hSI){
{ NRIG1v>
bStop = true; UMm!B`M
for(int i=0;i<nStartPos.length;i++) biU^[g("
fileSplitterFetch.splitterStop(); -7@/[9Gf`:
zGkS^Z=(
|8l<$J
} @v)p<r^M">
} @] DVD
//负责部分文件的抓取 }o?APvd
**FileSplitterFetch.java S79;^X
*/ eoG$.M"
package NetFox; |Sy<@oq
)I^7)x
SBfT20z[
import java.io.*; yDegcAn?
import java.net.*; Kzm+GW3o[
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3yU.& k
public class FileSplitterFetch extends Thread { (mTE;s(
~O oidKT
5A3xVN=
String sURL; //File URL 26I_YL,S
long nStartPos; //File Snippet Start Position W_\5nF
long nEndPos; //File Snippet End Position c|B.n]Z
int nThreadID; //Thread's ID !h23cj+V
boolean bDownOver = false; //Downing is over IYS)7`{]
boolean bStop = false; //Stop identical SwTL|+u
FileAccessI fileAccessI = null; //File Access interface }J:U=HJ
,*&:2o_r
_u5#v0Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $0>60<J
{ %7IugHH9y
this.sURL = sURL; p93r'&Q
this.nStartPos = nStart; t\k$};qJ
this.nEndPos = nEnd; @hiCI.?X
nThreadID = id; /'l{E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Cz\ew B
} _/-jX
4U+xb>
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public void run() |Mup8(gCk
{ =S+wCN
while(nStartPos < nEndPos && !bStop) ;o2$ Q
{ m.# VYN`+A
bYpntV
t^R][Ay&
try{ bnq;)>&
URL url = new URL(sURL); 'g=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cdl&9-}
httpConnection.setRequestProperty("User-Agent","NetFox"); .oYl-.E>&
String sProperty = "bytes="+nStartPos+"-"; :8=ikwQ
httpConnection.setRequestProperty("RANGE",sProperty); &_dt>.
Utility.log(sProperty); {JZZZY!n2
Tc>
.w=/+TA
InputStream input = httpConnection.getInputStream(); r~jm`y
//logResponseHead(httpConnection); \E72L5nJW
PV'x+bN5
4sF"6+%5d
byte[] b = new byte[1024]; m? J0i>H
int nRead; 1 d}Z(My
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u~7hWiY<2
{ H]{v;;'~
nStartPos += fileAccessI.write(b,0,nRead); C*)3e*T*
//if(nThreadID == 1) GP!?^r:en
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^84G%)`&
} rb5~XnJk
\o}xF@sM5
, pDnRRJ!
Utility.log("Thread " + nThreadID + " is over!"); %p^wZtm
bDownOver = true; 8=B|C'>
//nPos = fileAccessI.write (b,0,nRead); M -cTRd-i
} ww\CQ6/h
catch(Exception e){e.printStackTrace ();} l&OKBUG
} [842&5Pd?
} DBW[{DE
WejYy|
`<``8
//打印回应的头信息 :|V$\!o'U
public void logResponseHead(HttpURLConnection con) \HxT@UQ)~
{ q0i(i.h
for(int i=1;;i++) 8Wrh]egu1
{ !;&p"E|b#
String header=con.getHeaderFieldKey(i); R]}}$R`j
if(header!=null) ]i&6c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dt \TQJc~
Utility.log(header+" : "+con.getHeaderField(header)); ck ]Do!h
else BgurzS4-
break; dA@]!
} 8n#HFJ~
} PWaw]*dFmy
A-H&
FcR=v0),
public void splitterStop() T6O::o6
{ |%F=po>w
bStop = true; ~P*6ozSYpY
} 3m]4=
\8)U!9,$nn
lP[w?O
} Y}t \4 di
1tEgl\u\
wKtl+}}
/* kw>v:F<M
**FileAccess.java /[a~3^Gs^
*//文件访问(定位，写) q.KG^=10
package NetFox; 6Z>FTz_
import java.io.*; A>vBQN
UldXYtGe
5L+>ewl
public class FileAccessI implements Serializable{ wxR,OR
5gb|w\N>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v~f HYa>
RandomAccessFile oSavedFile; A;;fACF8e
long nPos; ciFmaM.
_Zp}?b5Q
nF54tR[
public FileAccessI() throws IOException |'.*K]Yp
{ 1Ce@*XBU
this("",0); yQ_B)b
} H7z,j}l
)JDs\fUE
9A/\h3HrJ
public FileAccessI(String sName,long nPos) throws IOException Hbj,[$Jb
{ #X%~B'
oSavedFile = new RandomAccessFile(sName,"rw"); }6p@lla,%]
this.nPos = nPos; PXK7b2fE.
oSavedFile.seek(nPos); \l'm[jy>
} Lz`E;k^
\s/s7y6b+
oiF}?:7Q7
public synchronized int write(byte[] b,int nStart,int nLen) ^ssK
{ MuYk};f
int n = -1; ;+e}aER&9
try{ O!mvJD
oSavedFile.write(b,nStart,nLen); 5QW=&zI`=
n = nLen; `_BNy=`s*
} fL_4uC i\
catch(IOException e) wg7V-+@i
{ w,.+IV$Kk
e.printStackTrace (); V@B__`y7
} -|J"s$yO4
HKU~UTRnZ
nim*/LC[:
return n; 3p39`"~
} ~k\fhx
h hG4-HD
J4QXz[dG
} 931bA&SL=/
aH 4c02s$
E[2m&3&
/* N^#ZJoR
**SiteInfoBean.java M}`B{]lLz
*/ 98j>1"8
package NetFox; =+/eLKG
&Lt}=3G
t#Z-mv:(
public class SiteInfoBean { E.r>7`E
/,89p&h
1%EBd%`#
private String sSiteURL; //Site's URL xe#FUS 3
private String sFilePath; //Saved File's Path yyoqX"v[
private String sFileName; //Saved File's Name nc~F_i=
private int nSplitter; //Count of Splited Downloading File s:OFVlC%\
1/RsptN"v
5A%w 8Qv
public SiteInfoBean() b1^vd@(lx
{//nSplitter的缺省值为5 Ozw;(fDaU
//default value of nSplitter is 5 t`WB;o!
this("","","",5); NhfJ30~
} rx $mk
r#+d&.|
zAK+8{,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fdxLAC
{ 1QqYQafA
sSiteURL= sURL; 8B7cBkl:
sFilePath = sPath; +vYoB$!
sFileName = sName; e&simX;W
this.nSplitter = nSpiltter; *v;!-F&8>
c]$i\i#
qHsUP;7
} k>F'ypm
bBu,#Mc
@PN#p"KaT
public String getSSiteURL() -u&6X,Oq\u
{ 9:fOYT$8
return sSiteURL; B.wYHNNV
} *meZ8DV2DH
c;%_EN%
wmk *h-
public void setSSiteURL(String value) >NqYyW,%
{ Ot:CPm@
sSiteURL = value; l\BVS)
} p`mS[bxv!
~3UQ|j
{p)",)td
public String getSFilePath() #,S0HDDHn
{ P::TO-C
return sFilePath; 9iXeBC
} G3{Q"^S"
rFIqC:=
6,"IDH|ND
public void setSFilePath(String value) 5j:0Yt
{ w3#Wh|LQ-
sFilePath = value; 7q?9Tj3
} ` BDLW%aL
L=c!:p|7)
9)0D~oUi
public String getSFileName() #OBJzf*p
{ lwHzj&/ ~
return sFileName; P.6nA^hXB
} %dJX-sm@
L>MLi3{
qgE 73.!`6
public void setSFileName(String value) k xP-,MD
{ ^cV;~&|.Xk
sFileName = value; $>*3/H
} _Bj)r}~7#
QN@CPuy
t/ +=|*
public int getNSplitter() `%CtWJ(e
{ anIAM
return nSplitter; )u3 Zm
} +hvO^?4j
z)'Mk[
Rz(QC\(
public void setNSplitter(int nCount) umD!2 w
{ km)zMoE{c{
nSplitter = nCount; e&7JpT
} ki[UV zd
} 0.dgoq3u
=.y~fA!
d_4T}%q
/* }tsYJlh5
**Utility.java }Mo=PWI1?
*/ EPS={w$'s
package NetFox; W.z;B<
lCAIK
ZaeqOVp/j
public class Utility { L~(_x"uXd
m0LTx\w!
*\=.<|HZ
public Utility() +u!0rLb
{ Wm_4avXtO
;FBUwR}
0|2%vh>J
} $wmvKQc{lx
uIcn{RZ_z
//线程睡眠 A'G66ei
public static void sleep(int nSecond) " Om[~-31
{ Y3r%B9~
try{ 2rmSo&3@s
Thread.sleep(nSecond); M>&%(4K
} A:aE|v/T&
catch(Exception e) :/:.Kb
{ 8aO~/i:(.
e.printStackTrace (); s_x:T<]
} @7n/Q(
} @kk4]:,w
-QOw8vm
//日志 {LX.iH9}l
public static void log(String sMsg) [QMu2
{ Sl-v W
System.err.println(sMsg); 4Fp0ZVT
} z74in8]
~vXaqCX
4D['^q
public static void log(int sMsg) =Vy`J)z9
{ Yu?95qktP
System.err.println(sMsg); <,3^|$c%
} %6L^2 X
} b8LoIY*
fQL"O}Z
1U^A56CN
/* YhOlxON
**TestMethod.java WA]c=4S
*/ ]Tkc-ez
package NetFox; q6_u@:3u
JL\w_v
5m?8yT}
public class TestMethod { xqC+0{]y
[F*.\
@fs`=lL/
public TestMethod() A3B56K
{ ///xx/weblogic60b2_win.exe vk*=4}:
try{ !PrwH;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _@ *+~9%8p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }b=}uiR#
SiteFileFetch fileFetch = new SiteFileFetch(bean); X>NhZ5\
fileFetch.start(); 1WY/6[
} COTp
catch(Exception e){e.printStackTrace ();} 8<.C3m 6h
66.5QD0
0j30LXI_
} )K,F]fc+O
#<e\QE'!
w"OP8KA:^T
public static void main(String[] args) ua5OGx
{ U f|> (C
new TestMethod(); R,9[hNHWGs
} 0A,]$Fzt
} }?z@rt^
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