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)); YDZB$?&a
} c[;A$P= 8.
for(int i=0;i<nEndPos.length-1;i++) xiL+s-
{ sGh TP/
nEndPos = nStartPos[i+1]; JxKd
} /8u}VYE
nEndPos[nEndPos.length-1] = nFileLength; :H#D4O8UiH
} >[~`rOU*|Y
} ztAC3,r]
:;IZ|hU
lanU)+U.
//启动子线程 I}|E_U1Qj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9ph>4u(R
for(int i=0;i<nStartPos.length;i++) (4IP&^j:\
{ ;kZJnN"y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q(R-8"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?X\uzu
nStartPos,nEndPos,i); n]nJ$u1u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )TBm?VMe
fileSplitterFetch.start(); =`2jnvx
} A'"J'q*t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~Q]/=HK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mE'HRv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H_ NoW
nEndPos = " + nFileLength); n0t+xvNDF_
// fileSplitterFetch[nPos.length-1].start(); wod(P73?
i[wnG)
:f7:@8
//等待子线程结束 /g8nT1k
//int count = 0; muDOY~.
//是否结束while循环 o)Px d
boolean breakWhile = false; R?dMM
fJ=(oF=
R%\<al$O
while(!bStop) {DE4PE`
{ X_)I"`
write_nPos(); "Y"`'U=v
Utility.sleep(500); 9JeT1\VvHY
breakWhile = true; Z`Jt6QgW
BAG#YZB
nITkgN:s
for(int i=0;i<nStartPos.length;i++) |x=(}g
{ ,#9i=gp
if(!fileSplitterFetch.bDownOver) F>?~4y,b7
{ "*TP@X?@f
breakWhile = false; ,Ww.W'#P
break; bIzBY+P
} &'/bnN +R
} 1uEM;O
if(breakWhile) QtcYFf g
break; {IF$\{Al
.4Mc4'
<p?oFD_e4
//count++; 8|u8J0^
//if(count>4) jN(c`Gb
// siteStop(); Tt_QAIl
} ,>nf/c0.
!<F5W<V
Gs4t6+Al
System.err.println("文件下载结束！"); i&<@}:,
} ] pv!Ll
catch(Exception e){e.printStackTrace ();} ]4'V59\
} q4vHsy36
'$4&q629d
OLGMy5
//获得文件长度 @Y ?p-&
public long getFileSize() 5kHU'D
{ VkId6k:>6C
int nFileLength = -1; M"Z/E>ne
try{ g>a% gVly
URL url = new URL(siteInfoBean.getSSiteURL()); _UbyhBl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ACI.{`SrQ=
httpConnection.setRequestProperty("User-Agent","NetFox"); ?\<Kb|Q
zs'Jgm.v
H1 i+j;RN
int responseCode=httpConnection.getResponseCode(); Y~I0\8s-
if(responseCode>=400) cet|k!
{ w;kiH+&
processErrorCode(responseCode); >#`{(^
return -2; //-2 represent access is error z)R\WFBW
} gEmsPk,
#8%~u+"N
#wGOlW;R
String sHeader; [t*-s1cq
@# .a5
roIc1Ax:
for(int i=1;;i++) a,:Nlr3
{ Sg(\+j=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _+Uf5,.5yU
//Utility.log(in.readLine()); {>Qs+]
sHeader=httpConnection.getHeaderFieldKey(i); COxJ,v(
if(sHeader!=null) 6rlM\k@!
{ b86c[2
if(sHeader.equals("Content-Length")) Ng*O/g`%L
{ xo(>nFjo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WpkCFp
break; Hx9lQ8
} @[5]?8\o
} /1hcw|cfC
else BtQqUk#L2
break; Lf;Uv[^c
} |9)y<}c5oM
} _1jeaV9@
catch(IOException e){e.printStackTrace ();} K~qKr<)
catch(Exception e){e.printStackTrace ();} w3Dqpo8E
0{stIgB$
g&/r =U
Utility.log(nFileLength); V|4k=_-
.G/RQn]x}
|KSoS#Y
return nFileLength; oCKn
} WVx^}_FD0
& 5'cN
/vqsp0e"H
//保存下载信息（文件指针位置） iP?lP= M
private void write_nPos() 7V"Jfh4_
{ H$,wg!kY!
try{ NH,4>mV$!
output = new DataOutputStream(new FileOutputStream(tmpFile)); %D ,(S-Uj
output.writeInt(nStartPos.length); 1Nz#,IdQ
for(int i=0;i<nStartPos.length;i++) |e2s{J2
{ fh&Q(:ZU
// output.writeLong(nPos); !6J+#
output.writeLong(fileSplitterFetch.nStartPos); Enhrkk
output.writeLong(fileSplitterFetch.nEndPos); zbDK$g6
} p0pA|
output.close(); v5L#H=P
} TezwcFqH
catch(IOException e){e.printStackTrace ();} Xs)?PE[
catch(Exception e){e.printStackTrace ();} 9hhYyqGsO
} py\/m]
wNl "y
8]JlYe
//读取保存的下载信息（文件指针位置） "g1Fg.o
private void read_nPos() @nM+*0 $d
{ >NA{**$0
try{ bhCAx W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |3gWH4M4**
int nCount = input.readInt(); VWMr\]g
nStartPos = new long[nCount]; -B:O0;f
nEndPos = new long[nCount]; p8z"Jn2P
for(int i=0;i<nStartPos.length;i++) ho6,&Bp8
{ k-$J #
nStartPos = input.readLong(); c`#4}$
nEndPos = input.readLong(); ZC&4uNUr
} Bs<LJzS{V
input.close(); e!4Kl:
} 1tH#QZIT
catch(IOException e){e.printStackTrace ();} z|zd=3c
catch(Exception e){e.printStackTrace ();} p49T3V
} ;{"uG>#R
U5j0i]
?xo<Fv
private void processErrorCode(int nErrorCode) 3\5I4#S
{ }ct*<zj[~u
System.err.println("Error Code : " + nErrorCode); XKbTjR
} S@C"tHD
<##aD3)
w6[$vib'
//停止文件下载 o q cu<]
public void siteStop() ?$4CgN-
{ \6,Z<.I
bStop = true; ypY7uYO^"
for(int i=0;i<nStartPos.length;i++) %?z;'Y7D
fileSplitterFetch.splitterStop(); L$}'6y/@
oRl@AhS
@Hst-H.l<l
} +/Vzw
} BWsD~Ft
//负责部分文件的抓取 bpfSe
**FileSplitterFetch.java @C5%`{\
*/ &0J/V>k
package NetFox; xf8.PqVNo
rB3b
Bzr}+J
import java.io.*; 58/\
import java.net.*; 2Zw]Uu`sb
suZ`
/S%!{;:
public class FileSplitterFetch extends Thread { |r53>,oR<:
6 ZVD<C:\
|(R[5q
String sURL; //File URL ZRCUM"R_
long nStartPos; //File Snippet Start Position %l)~C%T
long nEndPos; //File Snippet End Position r A9Rz^;xa
int nThreadID; //Thread's ID 9!Vp-bo
boolean bDownOver = false; //Downing is over b]\V~ZaXG
boolean bStop = false; //Stop identical ~Nl`Zmn(A|
FileAccessI fileAccessI = null; //File Access interface aB4L$M8x
@#| R{5=+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Rj,M|9Y)o
{ r7N%onx
this.sURL = sURL; n`7n5M*
this.nStartPos = nStart; ,NQ>,}a0
this.nEndPos = nEnd; x:IY6 l
nThreadID = id; u2Qs}FX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /4u:5G
} 8\8%FSrc
w7h=vy n?
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public void run() tqK}KL
{ 2&U<Wiu\}
while(nStartPos < nEndPos && !bStop) Px"K5c*
{ pXHeUBY.
&E8fd/s=k
" qrL:,
try{ %b`B.A
URL url = new URL(sURL); 0qD.OF)8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^->vUf7PX
httpConnection.setRequestProperty("User-Agent","NetFox"); !<MW*7P=
String sProperty = "bytes="+nStartPos+"-"; =DXvt5G
httpConnection.setRequestProperty("RANGE",sProperty); IctLhYZ
Utility.log(sProperty); ]lzOz<0q
Z(fhH..T`
8^dsx1U#
InputStream input = httpConnection.getInputStream(); z50f$!?
//logResponseHead(httpConnection); gb/M@6/j
MHKB:t]hA
t~"DQqE
byte[] b = new byte[1024]; _a=f.I
int nRead; MOW {g\{\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R|H_F#eVn}
{ 4lfJc9J
nStartPos += fileAccessI.write(b,0,nRead); ihdtq
//if(nThreadID == 1) Vl+,OBy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >jDx-H.N
} 1 +'HKT}
? /Z hu
>w=xGb7
Utility.log("Thread " + nThreadID + " is over!"); E={W^k!Vz:
bDownOver = true; :WBl0`kW]4
//nPos = fileAccessI.write (b,0,nRead); f*SAbDE
} g8_IZ(%:
catch(Exception e){e.printStackTrace ();} }ZWeb#\
} '%"#]
} p,w6D,h
Ey"<hAF
^~dvA)bH
//打印回应的头信息 +(<}`!9M*
public void logResponseHead(HttpURLConnection con) v+Q#O[
{ ".SQ*'Oc
for(int i=1;;i++) kY6))9 O
{ -m~[z
String header=con.getHeaderFieldKey(i); e?D,=A4mV"
if(header!=null) %C[ ;&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lEC58`Ws
Utility.log(header+" : "+con.getHeaderField(header)); P&Q 5ZQb
else 3It'!R8$
break; 4n@, p0
} [Pt5c6L:
} V-w[\u
ynN[N(m#
G{ $Zg
public void splitterStop() %R{clbbbn
{ -h8!O+7 .
bStop = true; }?Y+GT"E
} }f6x>
1v&!`^G99j
? I}T[j
} z {J1pH_X
a;Y9wn
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/* w`Dzk.2
**FileAccess.java EF{_-FXY
*//文件访问(定位，写) -3r&O:
package NetFox; !lF|90=
import java.io.*; 6X:-Z3
#|8!0]n'
T`=N^Ca1!`
public class FileAccessI implements Serializable{ QE5 85s5
|[TH ~o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N3H!ptn37
RandomAccessFile oSavedFile; b`K~l'8
long nPos; B%9[
E4[\lX$J
|[|X
public FileAccessI() throws IOException [:!#F7O-
{ 6|LDb"Rvy
this("",0); >|7&hj$
} _ #l b\
eeb8v:4
^LT9t2
public FileAccessI(String sName,long nPos) throws IOException #D+Fq^="P
{ V|HSIJ#J
oSavedFile = new RandomAccessFile(sName,"rw"); fC%;|V'Nd
this.nPos = nPos; >e-XZ2>Sj
oSavedFile.seek(nPos); 1xq1te)
} }+#ag:M
JEBo!9
D?5W1m]E,s
public synchronized int write(byte[] b,int nStart,int nLen) |_[mb(<|
{ 0#*\o1r\p
int n = -1; 2#W%--
try{ 7@tr^JykO
oSavedFile.write(b,nStart,nLen); PLo.q|%
n = nLen; -R7f/a8
} ]\r~"*TZ
catch(IOException e) x5`q)!<&
{ e$>5GM
e.printStackTrace (); N{p2@_fnB
} !>S'eXt
QTn-n)AE
S-f3rL[?
return n; ^2^ptQj
} Ha C?,
U;V. +onv
@fE^w^K7
} dEe/\i'r9
GF/p|I D
v@t*iDa?7
/* o!\O)
**SiteInfoBean.java / V{w<
*/ :Dr& {3>
package NetFox; :&or'Yi}
7L-%5:1%
G0]n4"~+?
public class SiteInfoBean { HWefuj
Bgs~1E@8V
v\MH;DW^Z
private String sSiteURL; //Site's URL H`Z4a N
private String sFilePath; //Saved File's Path {YGz=5^
private String sFileName; //Saved File's Name G0(c@FBK
private int nSplitter; //Count of Splited Downloading File O5=ggG
MZd\.]G@
rf`Br\g8
public SiteInfoBean() k=~?!+p7
{//nSplitter的缺省值为5 h |lQTT
//default value of nSplitter is 5 5r+0^UAO:J
this("","","",5); 1I@4xC #X
} rL,)Tc|"
CMg83
*xl7;s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `Eu(r]:W
{ KqSa"76R
sSiteURL= sURL; n5JB'F)
sFilePath = sPath; k0YsAa#6V
sFileName = sName; f C^l9CRY
this.nSplitter = nSpiltter; n47=eKd70
kCwTv:)
&=?`;K
} :U:7iP:
j0%0yb{-^
Qr<%rU^{.
public String getSSiteURL() wU ; f
{ $HXB !$d
return sSiteURL; p;7 4+q
} `HS4(2+C
wrO>#`Z
<{U{pCT%
public void setSSiteURL(String value) @*uX[)
{ _ <;Q=?'*
sSiteURL = value; 5j{@2]i
} `Of wl%G
5i/E=D
YDNqWP7s
public String getSFilePath() Ij#a
{ VBX# !K1Q
return sFilePath; @*DIB+K
} |x6mkSf]ke
Y1 P[^ws
:xw3b)KS
public void setSFilePath(String value) 4{DeF@@
{ )RYnRC#O
sFilePath = value; |wJZU
} )KqR8UO
=GQ^uVf1
eCp|QSXE
public String getSFileName() tqQ0lv^J
{ mei_aN7zW
return sFileName; lkfFAwnc
} VWshFI
Is@a,k
O^}v/}d
public void setSFileName(String value) |"yf@^kdC
{ *|HZ&}
sFileName = value; s1vrzze
} %EGr0R(
Fd[h9 G
B~>cNj<
public int getNSplitter() .gN$N=7<
{ >J}n@MZ
return nSplitter; v{2DBr
} t;!]z-Y>
JYd7@Msfc
9*KMbd^T
public void setNSplitter(int nCount) T;4`wB8@
{ Iz)hz9k
nSplitter = nCount; JblmXqtC
} m`$>:B
} lB!vF ~A&
90T%T2K
Lq-33#n/
/* |:9Ir^
**Utility.java 5}eQaW48
*/ `xUG|
package NetFox; 3%R{"Q"
+%wWSZ<#
R|1xXDLm*E
public class Utility { 0HR|aqPo
ck+b/.gw`
qon{ g
public Utility() `4%;qLxngP
{ 5_)@B]~nM
3eTrtCe$
*v rWA
} !\0F.*
OB6J.dF[%
//线程睡眠 [8@kxCq
public static void sleep(int nSecond) 6z3T?`}Y
{ Cqgk
try{ nG"n-$A?<
Thread.sleep(nSecond); kT^*>=1
} =4zNo3IvL+
catch(Exception e) ejklpa ./
{ Xlv#=@;O]
e.printStackTrace (); Y}LLOj@L
} #, Q}NO#vT
} RzS|dGNQE
'Y!pY]Z
//日志 'j,oIqx
public static void log(String sMsg) Dz`k[mI
{ jJ aV
System.err.println(sMsg); ?j/kOD0
} Wp5]Uk
aDL)|>"Q
{'h_'Y`bOQ
public static void log(int sMsg) #JA}LA"l
{ QCOLC2I
System.err.println(sMsg); fcRj
} dEASvD'
} Q.,DZp
z)lM2x>|*
W+gpr|R2
/* yl-fbYH
**TestMethod.java fVe@YqNa
*/ \M5P+Wk'
package NetFox; D_d|=i
}[ ].\G\G
vwKw?Z0%J
public class TestMethod { L=,OZ9aA
<uZPqi||
K@HQrv<
public TestMethod() +W9]ED
{ ///xx/weblogic60b2_win.exe %3M95UZ2
try{ TPHYz>D]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2H[ ; v+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p8=|5.
SiteFileFetch fileFetch = new SiteFileFetch(bean); Qyz>ZPu}sz
fileFetch.start(); x;u~NKy
} 4O!E|/`wO
catch(Exception e){e.printStackTrace ();} F>N+<Z
p*|ah%F6N
vMhYpt?7\
} :BZMnCfA
R2w`Y5#`
&5u BNpH
public static void main(String[] args) *g1L$FBG
{ dK.R[aQ
new TestMethod(); 6xarYh(
} iJ)0Y~
} B7HQR{t
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