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)); N*.JQvbnr
} zZ3Ko3L%g_
for(int i=0;i<nEndPos.length-1;i++) V+7x_>!&)
{ GC(:}e|
nEndPos = nStartPos[i+1]; eil"1$k
} 83,ATQg
nEndPos[nEndPos.length-1] = nFileLength; &Q7vY
} ?nOul}y/
} 2/.Euf
n6T@A;_g
iU^KmM I
//启动子线程 DgOO\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h+o-h4X
for(int i=0;i<nStartPos.length;i++) s53Pw>f
{ h WvQh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `usX(snY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1#H=<iJ
nStartPos,nEndPos,i); *QAcp` ;*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,v;P@RL|g
fileSplitterFetch.start(); 6 /8?:
} E?> ERO3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W79wz\a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7hPiPv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", > %5<fK2
nEndPos = " + nFileLength); +o]DT7W
// fileSplitterFetch[nPos.length-1].start(); -3 .Sr|t
b(8#*S!U
Yj+p^@{S2P
//等待子线程结束 OZ2gIK
//int count = 0; n_[;2XQQ
//是否结束while循环 @ToY,@]e
boolean breakWhile = false; Kj|l]'
OQt_nb#z`{
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while(!bStop) ?Rlo<f:Mf
{ @1_M's;
write_nPos(); HyKvDJ 3_
Utility.sleep(500); ay}}v7)GM
breakWhile = true; };5d>#NK,Y
v8Ga@*
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for(int i=0;i<nStartPos.length;i++) eH.~c3o
{ 2H7b2%
if(!fileSplitterFetch.bDownOver) R pUq#Y:a
{ 3o=R_%r
breakWhile = false; r(g:b ^S
break; e nsou!l
} 15NeC7GAh
} @edx]H1~^
if(breakWhile) p*F.WxB)4
break; 49vKb(bz{
neN #Mo'A
QDO.&G2
//count++; }=.:bwX5
//if(count>4) Gt>*y.]
// siteStop(); A.0eeX{
} Bf {h\>q
mUFg(;ya
`;?`XC"m
System.err.println("文件下载结束！"); HV_5 +
} QahM)Gb
catch(Exception e){e.printStackTrace ();} /l o;:)AiP
} )YSS>V
$9LI v
9|y?jb5im
//获得文件长度 -_<rmR[:]
public long getFileSize() E?,O>bCJ5
{ 6|h~pH
int nFileLength = -1; Yz6+ x]
try{ >"}z % #
URL url = new URL(siteInfoBean.getSSiteURL()); J['pBlEb\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (e,5 b
httpConnection.setRequestProperty("User-Agent","NetFox"); 1?6zsA%N
pAZD>15l"
t|/{oAj
int responseCode=httpConnection.getResponseCode(); ~yrEB:w`_
if(responseCode>=400) HN7C+e4U~
{ s48 { R4
processErrorCode(responseCode); 2h:*lV^
return -2; //-2 represent access is error ak_&\'P
} 0+H4sz%.
wtm=
)HaW# ,XB
String sHeader; m+Um^:\jX
3b9SyU2
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for(int i=1;;i++) P LHiQ:
{ NG)Xk[q4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qv v~nGq$
//Utility.log(in.readLine()); Ms * `w5n
sHeader=httpConnection.getHeaderFieldKey(i); fWutB5?P
if(sHeader!=null) *=b#>//
{ !Z0p94L
if(sHeader.equals("Content-Length")) f_{OU E
{ `XmT)C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,)u7PMs
break; ZSs)AB_Pe/
} /E%r@Rui3$
} f&ZFG>)6
else 0P?\eoB@8
break; aC2cyUuaN
} rzk]{W
} 8dBG ZwyET
catch(IOException e){e.printStackTrace ();} ";>>{lYA.
catch(Exception e){e.printStackTrace ();} &IZthJqV
IegZ)&_n
,xhB
Utility.log(nFileLength); ue/GB+U
^y1P~4w?
i!tF{'*%#
return nFileLength; -_4ZT^.Lna
} "&@v[O)!xu
`3QAXDWE
d^.@~
//保存下载信息（文件指针位置） <}vult^
private void write_nPos() Qr n^T
{ VQMPs{tm
try{ '9w.~@7
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~8htg8CZ`
output.writeInt(nStartPos.length); Y*KHr`\C4
for(int i=0;i<nStartPos.length;i++) F~C9,`#Wf@
{ ~"t33U6
// output.writeLong(nPos); L<`p;?
output.writeLong(fileSplitterFetch.nStartPos); X (0`"rjg
output.writeLong(fileSplitterFetch.nEndPos); Wu\szI"
} mv0JD(
output.close(); Kx@Papn|6
} 7^3a296
catch(IOException e){e.printStackTrace ();} A=+ |&+? t
catch(Exception e){e.printStackTrace ();} i_KAD U&mP
} >h>
hG8!aJo
R{X@@t9@
//读取保存的下载信息（文件指针位置） 55<f
private void read_nPos() $Qc`4x;N
{ -9(9LU2
try{ p^yuz (
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vnrP;T=^
int nCount = input.readInt(); DNu^4#r
nStartPos = new long[nCount]; #+<"`}]N
nEndPos = new long[nCount]; |oL}c!0vs
for(int i=0;i<nStartPos.length;i++) iFi6,V*PRt
{ 2/coa+Qkv]
nStartPos = input.readLong(); M|l`2Hpe
nEndPos = input.readLong(); B>!OW2q0D
} ,Zs"r}G^
input.close(); T`?{Is['(
} ,o\-'
catch(IOException e){e.printStackTrace ();} G5R"5d'
catch(Exception e){e.printStackTrace ();} s>VpbJ3S
} kg@Okz N%
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~53uUT|B
private void processErrorCode(int nErrorCode) x_yQoae
{ e=yQFzQT)
System.err.println("Error Code : " + nErrorCode); K:osfd
} w}`TJijl
nB#m?hK
?df*Y5I2
//停止文件下载 n&j@7R
public void siteStop() $}*bZ~
{ , Ac gsC
bStop = true; 2c Pd$j
for(int i=0;i<nStartPos.length;i++) C(Bh<c0@
fileSplitterFetch.splitterStop(); B]""%&! O
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-!~T$}/F
} I>(3\z4s
} ^)|!nd
//负责部分文件的抓取 ]V4Fm{]
**FileSplitterFetch.java p;P"mp\'
*/ ,'KS:`m!
package NetFox; ?c$z?QTMJ
k/hD2tBLu
de&*#O5
import java.io.*; zOEdFU{x
import java.net.*; R;6$lO8C&
Tf|?j=f
VN5UJ!$?J
public class FileSplitterFetch extends Thread { 49gm=XPm
Ui^~A
^ |xSU_wa
String sURL; //File URL a___SYl 'K
long nStartPos; //File Snippet Start Position h}T+M BA%
long nEndPos; //File Snippet End Position H;eGBVi
int nThreadID; //Thread's ID e?V7<7$
boolean bDownOver = false; //Downing is over 0pC}+ +
boolean bStop = false; //Stop identical 9ozK}Cg4
FileAccessI fileAccessI = null; //File Access interface ;$\?o
y,.X5#rnX*
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YM:;mX5B
{ W`qiPLk
this.sURL = sURL; =}$YZuzmU
this.nStartPos = nStart; p H5iv>H
this.nEndPos = nEnd; |\ZsoA
nThreadID = id; qId-v =L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m,u5S=3A{!
} l$1z%|I
vLc7RL
0c$0<2D%
public void run() ?tf/#5t}
{ em@bxyMm
while(nStartPos < nEndPos && !bStop) _>6xUt
{ sp/l-a
V[w Y;wj
':mw(`
try{ lJ'.1Z&
URL url = new URL(sURL); Q?Y\WD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1feZ`P;
httpConnection.setRequestProperty("User-Agent","NetFox"); {hXIP`
String sProperty = "bytes="+nStartPos+"-"; 4)cQU.(*k
httpConnection.setRequestProperty("RANGE",sProperty); XMR$I&;G8
Utility.log(sProperty); w;=fi}<G|e
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[32]wgw+{1
InputStream input = httpConnection.getInputStream(); |<Cz#| ,q
//logResponseHead(httpConnection); 3k#?E]'
ae&i]K;
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byte[] b = new byte[1024]; TpHvZ]c
int nRead; d~G, *
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'V*ixK8R0
{ ed=pRb
nStartPos += fileAccessI.write(b,0,nRead); s!vvAD;\
//if(nThreadID == 1) \NiW(!Z}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?^8CD.|
} xbN)z
]\qbe
Eeumi#$Z
Utility.log("Thread " + nThreadID + " is over!"); 2/T4.[`t
bDownOver = true; k^JV37;bl
//nPos = fileAccessI.write (b,0,nRead); c]eDTbXd
} !4"!PrZDB
catch(Exception e){e.printStackTrace ();} zq:+e5YT?T
} 0ESxsba
} e%Sw(=a
a5)<roWQ
up# R9 d|
//打印回应的头信息 b`lLqV<[cB
public void logResponseHead(HttpURLConnection con) ~x!"(
{ y@T0 jI
for(int i=1;;i++) :RxWHh3O
{ S .KZ)
String header=con.getHeaderFieldKey(i); B7*^rbI:X
if(header!=null) ?4[IIX-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k\ 2.\Lwb
Utility.log(header+" : "+con.getHeaderField(header)); $$,/F
else C1x"q9|\`
break; y7x&/2
} BA5b;+o-
} 8zOoVO
Pl>BTo>p'
A;06Zrf1
public void splitterStop() b3zxiq x
{ )P>}uK;
bStop = true; &|d6
} (=T%eJ61
{mkD{2)KQ
vFz#A/1
} 4YT d
oB$P6
aw3 oG?3I
/* [myIcLp^aP
**FileAccess.java Xf"B\%,(`
*//文件访问(定位，写) oZ/z{`
package NetFox; snH9@!cG8
import java.io.*; 0bcbH9) 1q
(59u<F
\qo}}I>e
public class FileAccessI implements Serializable{ bW/^2B
R)>F*GsR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?}n\&|+
RandomAccessFile oSavedFile; 19g-#H!
long nPos; A~!v+W%vO1
.!B>pp(9
C{5bG=Sg~
public FileAccessI() throws IOException R9!GDKts%
{ ; xz}]@]Ar
this("",0); O1 KT
} Z ZMz0^V
I?z*.yA*
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public FileAccessI(String sName,long nPos) throws IOException Hy*_4r
{ W`d\A3v
oSavedFile = new RandomAccessFile(sName,"rw"); T1([P!g*
this.nPos = nPos; /Cl=;^)
oSavedFile.seek(nPos); Gy3t
} -Y{=bZS u
pSPVY2qKX
HgY>M`U
public synchronized int write(byte[] b,int nStart,int nLen) )[Bl3+'
{ CZ~%qPwDw
int n = -1; $3BH82
try{ p bT sn
oSavedFile.write(b,nStart,nLen); ?kF_C,k/>N
n = nLen; #cF ?a5
} CkHifmc(u-
catch(IOException e) Mqk[+n
{ dB=aq34l
e.printStackTrace (); qGYru1
} pAm L
U.kTdNSp
gE}+`w/X
return n; `nvm>u~[Hq
} &y~~Z [.F,
&l<~Xd#
L+]|-L`S
} 9?6]Zag
(9A`[TRwi
jW!x!8=
/* 5RUhrE
**SiteInfoBean.java 5TB==Fj ?
*/ i+Fk
package NetFox; h%0FKi^
,iy;L_N
Z'V"nhL
public class SiteInfoBean { y?}R,5k
+Y9n@`
#6'+e35^8
private String sSiteURL; //Site's URL ;"1
private String sFilePath; //Saved File's Path br[n5
private String sFileName; //Saved File's Name H*H=a
private int nSplitter; //Count of Splited Downloading File _-mJI+^/
Ed^F_Gg#
pn._u`xMV
public SiteInfoBean() Fb^Ae6/i
{//nSplitter的缺省值为5 X^%E"{!nU
//default value of nSplitter is 5 $&@etsW0/
this("","","",5); Bt?.8H6Y
} JKMcdD?'
`SN?4;N0
yJMHm8OB7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (e~vrSk+)~
{ K;NaiRP#k
sSiteURL= sURL; b~L8m4L
sFilePath = sPath; mKh<M)Bz
sFileName = sName; n?EL\B
this.nSplitter = nSpiltter; Zi4Ektj2
Kd%>:E*
0D=7Mef
} ZBf9Upg
J nzI- y
f|cF[&wo
public String getSSiteURL() "?Mf%u1R
{ ;<~lzfs
return sSiteURL; xdV $dDCT
} #2U4}#Mi
rjJ-ZRs\
1 xu2$x.b
public void setSSiteURL(String value) w?db~"T
{ uV'w0`$y
sSiteURL = value; TXDb5ZCzM
} HXg4 T
]L?DV3N
w*3DIVlxL
public String getSFilePath() H5'Le{
{ w]Fi:kV
return sFilePath; 4[$D3,A
} 3~uWrZ.u
&9*MO
R{hq1-
public void setSFilePath(String value) d mj T$a|
{ ?xgrr7
sFilePath = value; N`Q[OFe
} 0 3/<A^
)b_ GKA `
::Nhs/B/
public String getSFileName() 7Hm/g
{ `Y5{opG7-
return sFileName; k"V@9q;*
} #VA8a=t
*G,'V,?
z#|#Cq`VG
public void setSFileName(String value) ncy?w e
{ ji~P?5(:
sFileName = value; Z%uDz3I\Q"
} C6neZng
ly)b=ph&
"~uo4n~H
public int getNSplitter() G^ 2a<?Di
{ wV,l }Xb-
return nSplitter; ,7{}}l
} df$VC
nLfITr|5
]rs7%$ZW
public void setNSplitter(int nCount) \XUG-\$p
{ ~_YU%y
nSplitter = nCount; 5Tt%<#4
} o3oAk10
} ONkHHyT
M\f1]L|8d
4XprVB
/* U'8ub(:&
**Utility.java \1p_6U7
*/ <X{hW^??)
package NetFox; f/VrenZ_
dLtn,qCX0^
"Y7 ]t:8
public class Utility { !83N. gN
KC`~\sYRN]
Q;3v ]h_
public Utility() 4GY:N6qe'
{ tluyx
L< gp "e
iQI$Y]Y7
} q|[P[7z
yM8<)6=
//线程睡眠 ^6Std x_
public static void sleep(int nSecond) .$k2.-k
{ mOUIGlv
try{ O+o4E?}
Thread.sleep(nSecond); jC)lWD
} t[.wx.y&0
catch(Exception e) njk1x
{ y.LJ5K$&a
e.printStackTrace (); xGzp}
} qhPvU( ,
} V@(7K0
ARZ5r48)
//日志 l/JE}Eg(
public static void log(String sMsg) zMXlLRC0
{ :IZ(9=hs
System.err.println(sMsg); ?rD`'B
} Ifc}=:nr
l{{wrU`
,a$?KX
public static void log(int sMsg) kUdl2["MZ
{ nA\9UD<G.
System.err.println(sMsg); 4l2xhx
} es` A<
} BE;J/
JVORz-uBs
#0hX'8];(
/* nVTCbV
**TestMethod.java _V9 O,"DDc
*/ KXgC]IO~
package NetFox; &tULSp@J
}Ot I8;>
G$5N8k[2
public class TestMethod { +!I7(gL
xz+Y1fYT
$=c79Al(
public TestMethod() NdS6j'%B@7
{ ///xx/weblogic60b2_win.exe M=n_;3,o
try{ 9\/T #EP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J#0oL_xY#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Kzs]+Cl
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,=9e]pQ
fileFetch.start(); Dm=Em-ST6
} G n_AXN
catch(Exception e){e.printStackTrace ();} da[u@eNrnX
uF!3a$4]
yW$ja|^E
} pX:FXzYQ
wXc"Car)
ERW>G{+
public static void main(String[] args) 93Yo}6>
{ fwojFS.K
new TestMethod(); [I;5V=bKW
} 1GnT^u y/
} &AMW?vO
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