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)); jR#g>MDKB
} O#E]a<N`
for(int i=0;i<nEndPos.length-1;i++) /K"koV;
{ /JfRy%31
nEndPos = nStartPos[i+1]; q]Cmaf(
} mRw &^7r
nEndPos[nEndPos.length-1] = nFileLength; z17x%jXy
} %klC& _g~_
} dhW)<
^xO CT=V
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//启动子线程 uFIr.U$V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^E8XPK]-~
for(int i=0;i<nStartPos.length;i++) @O/-~,E68
{ %W=S*"e-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <8>gb!DG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MkG3TODfHB
nStartPos,nEndPos,i); X9#;quco@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AAE8j.
fileSplitterFetch.start(); Tt.wY=,K
} ?A/+DRQ(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wG4=[d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QcGyuS.B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1;R1Fj&
nEndPos = " + nFileLength); V6Y:l9
// fileSplitterFetch[nPos.length-1].start(); $UAmUQg)}_
CxC&+';
|"vUC/R2&
//等待子线程结束 N246RV1W
//int count = 0; -gl7mO*
//是否结束while循环 -aPvls
boolean breakWhile = false; SNB>
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18pi3i[
while(!bStop) q/[)Z @&(
{ QXnL(z
write_nPos(); , [xDNl[Y|
Utility.sleep(500); -9)<[>:
breakWhile = true; F'DO46
X|)Ox ,(
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for(int i=0;i<nStartPos.length;i++) hmv"|1Sa!~
{ Iq`:h&'!L
if(!fileSplitterFetch.bDownOver) f\FubL
{ y,i:BQJ<
breakWhile = false; }u0t i"V
break; Bkvh]k;F8
} qh!2dj
} Np=IZnpt
if(breakWhile) lV/-jkR
break; 6C>"H
c8I : jDk:
Nh7+Vl
//count++; A\9QgM
//if(count>4) R87-L*9B^0
// siteStop(); xwr<ib:
} i>w'$ {
>L F y:a
YoV^Y&:9<
System.err.println("文件下载结束！"); &)@|WLW
} AOhfQ:E 4
catch(Exception e){e.printStackTrace ();} $IzhaX
} fGDR<t3yiQ
sf\p>gb
47b=>D8
//获得文件长度 g/&`NlD
public long getFileSize() 6\ g-KO
{ m0+X 109
int nFileLength = -1; :|3n`,
try{ SnsOuC5Ah
URL url = new URL(siteInfoBean.getSSiteURL()); kYBy\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7jIye8Zi8
httpConnection.setRequestProperty("User-Agent","NetFox"); F3$@6J8<[z
$gU6=vN1#
~{7/v
int responseCode=httpConnection.getResponseCode(); kZXsL
if(responseCode>=400) s*<\mwB
{ 8C1 'g7A<
processErrorCode(responseCode); RM8p[lfX
return -2; //-2 represent access is error ]03+8#J
} j3`#v3
Gj^JpG
`,XCD-R^
String sHeader; \^O#)&5 V
##~";j
c+:LDc3!Gb
for(int i=1;;i++) RO(~c-fV
{ spIkXEK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GMqeC
//Utility.log(in.readLine()); @C]]VE
sHeader=httpConnection.getHeaderFieldKey(i); 1oq5|2p
if(sHeader!=null) Gzxq] Mg
{ jU\vg;nr
if(sHeader.equals("Content-Length")) qP6YnJWl
{ Uf#.b2]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kk_$j_0
break; k*)O]M<,
} ^.5`jdk
} 8zv=@`4@G
else }}Gz3>?24=
break; ^V]DQ%v"I
} #w\Bc\
} o RT<h
catch(IOException e){e.printStackTrace ();} egcJ@Of
catch(Exception e){e.printStackTrace ();} 2%Bq[SMuN
+X)n}jh
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Utility.log(nFileLength); HAa2q=
oxkA+}^j8M
EugQr<sM#
return nFileLength; X=O}k&
} 6% +s`
`NIc*B4q.
gd~# uR\
//保存下载信息（文件指针位置） zrD];DP
private void write_nPos() &?\'Z~B4
{ > <cK
try{ 1<Fh aK
output = new DataOutputStream(new FileOutputStream(tmpFile)); hs'J'~a
output.writeInt(nStartPos.length); wfr+-
for(int i=0;i<nStartPos.length;i++) g wM~W
{ ,})x1y
// output.writeLong(nPos); Q2[@yRY/z
output.writeLong(fileSplitterFetch.nStartPos); N\ nr
output.writeLong(fileSplitterFetch.nEndPos); So &c\Ff
} T8|aFoHCK
output.close(); F0,-7<G
} N<bNJD}
catch(IOException e){e.printStackTrace ();} *LnY}#
catch(Exception e){e.printStackTrace ();} ?@W=bJ8{
} ,0ZkE}<=w
\wW'Hk=
(x7AV$N
//读取保存的下载信息（文件指针位置） Y@WCp
private void read_nPos() ?U~}uG^
{ q}Wd`>VDR
try{ QIl![%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '^Kmfc
int nCount = input.readInt(); uM3F[p%V^
nStartPos = new long[nCount]; -cW`qWbd
nEndPos = new long[nCount]; xsjJ8>G
for(int i=0;i<nStartPos.length;i++) .O9A[s<
{ 2K/+6t}
nStartPos = input.readLong(); Wl3jbupu _
nEndPos = input.readLong(); ISo{>@a-
} 5X^bvW26
input.close(); BzFD_A>j;_
} a|B^%
catch(IOException e){e.printStackTrace ();} XRU^7@Ylks
catch(Exception e){e.printStackTrace ();} B-63IN
} }T!2IaAB
AEx|<E0
UPtWj8h
private void processErrorCode(int nErrorCode) xgl~4
{ eM)E3~K:2
System.err.println("Error Code : " + nErrorCode); ,>-Q#
} Zkn$D:
iy&*5U
:/e=J
//停止文件下载 v` 9^?Xw)
public void siteStop() A/kRw'6
{ <.c@l,[.z
bStop = true; JDO5eEwj
for(int i=0;i<nStartPos.length;i++) Y,1sNg
fileSplitterFetch.splitterStop(); p)M\q fZ
~z''kH=e
J:M)gh~#
} 9A]XuPAlh
} QInow2/u
//负责部分文件的抓取 Bsm>^zZ`YU
**FileSplitterFetch.java $)OUOv
*/ h'8w<n+%)
package NetFox; 7Gb(&'n
0(9]m)e
N7lWeF
import java.io.*; yKR0]6ahA
import java.net.*; ;9cBlthh
u*R9x3&/5
t(SSrM]
public class FileSplitterFetch extends Thread { ;d17xu?ks
6MC*2}W
1c=Roiq
String sURL; //File URL xJ"CAg|B
long nStartPos; //File Snippet Start Position 'TPRGX~&
long nEndPos; //File Snippet End Position j[/'`1tOe
int nThreadID; //Thread's ID \-c8/=
boolean bDownOver = false; //Downing is over >m!l5/
boolean bStop = false; //Stop identical <,~ =o
FileAccessI fileAccessI = null; //File Access interface iR-MuDM
13s0uyYU<m
YM9oVF-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A[juzOn\
{ h3^&,U
this.sURL = sURL; -la~p~8
this.nStartPos = nStart; Is6<3eQ\x
this.nEndPos = nEnd; q?C)5(
nThreadID = id; Ov{fO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bTzVmqGY
} 1m-"v:fT5D
lu@#)
H~~I6D{8
public void run() Ty]/F+{
{ UV>^[/^O
while(nStartPos < nEndPos && !bStop) #&\hgsw/T
{ tK&.0)*=
)2X ng_,
X-di^%<
try{ [woR9azC
URL url = new URL(sURL); 0y4z`rzTn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }z&P^p)R
httpConnection.setRequestProperty("User-Agent","NetFox"); Y[8w0ve-g
String sProperty = "bytes="+nStartPos+"-"; @URLFMFi
httpConnection.setRequestProperty("RANGE",sProperty); nbYkr*: "t
Utility.log(sProperty); H3 _7a9
FAu G`zu
an3HKfv
InputStream input = httpConnection.getInputStream(); T6f{'.w
//logResponseHead(httpConnection); Mj$dDtw
WNTm
vx=I3o
byte[] b = new byte[1024]; n5_r 3{
int nRead; '3uj6Wq2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~B%EvG7:n
{ :>lica_
nStartPos += fileAccessI.write(b,0,nRead); v>Il#
//if(nThreadID == 1) |dNtM^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZNPzQ:I@
} x_Ki5~w5
:=04_5 z
?,r bD1
Utility.log("Thread " + nThreadID + " is over!"); "fLGXbNQ
bDownOver = true; [d!C6FT
//nPos = fileAccessI.write (b,0,nRead); @18@[ :d"
} xM%E;
catch(Exception e){e.printStackTrace ();} (5d~0
} lwLK#_5u
} R~b9)
B$7m@|p!
bxP>
//打印回应的头信息 @1P1n8mH]
public void logResponseHead(HttpURLConnection con) s<qSelj
{ :o$ R@l
for(int i=1;;i++) @u/<^j3Q
{ uqZLlP#&#
String header=con.getHeaderFieldKey(i); bl\44VK2'
if(header!=null) $X5~9s1Wl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -mZo`
Utility.log(header+" : "+con.getHeaderField(header)); ?{qw /&
else vnz.81OR
break; t; n6Q0
} h`%K\C
} 14\%2nE
~0?p @8
S$]:3
public void splitterStop() L4sN)EI
{ h_]3L/
bStop = true; 9G_=)8sOV
} 5S7`gN.
17{]QuqNF
^g[\.Q
} nx=#QLi
"<6pp4*I
[RD ^@~x
/* !gy'_Y
**FileAccess.java Hi|2z5=V
*//文件访问(定位，写) <Xy8}Z`s
package NetFox; L5yxaF{]
import java.io.*; N(&FATZUW
/db?ltb
~1Tz[\H#R
public class FileAccessI implements Serializable{ T-&CAD3 ,O
~N[hY1}X[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CpS'2@6
RandomAccessFile oSavedFile; Beqhe\{
long nPos; =&"Vf!7YR7
^yK94U;<Gy
G !1- 20
public FileAccessI() throws IOException f'FY<ed<w
{ W~k!qy `
this("",0); [&nwB!kt
} U]R?O5K
8tA.d.8
wt2S[:!p
public FileAccessI(String sName,long nPos) throws IOException 3N+P~v)T'
{ /F;*[JZIb
oSavedFile = new RandomAccessFile(sName,"rw"); .F#mT h
this.nPos = nPos; Q77qrx3
oSavedFile.seek(nPos); Ef,@}S
} &;)~bS(
r %0
U_}$QW0'
public synchronized int write(byte[] b,int nStart,int nLen) 42p6l
{ ~n[LL)v
int n = -1; 7gVWu"
try{ sQJM 4'8f
oSavedFile.write(b,nStart,nLen); qsvUJU
n = nLen; 3jS=
} <Dm6CH
catch(IOException e) +{hxEDz
{ y^@%Xrs
e.printStackTrace (); 5.?O PK6
} Y ga}8DU
tEN]0`
K+v 250J$-
return n; #0`"gR#+
} ynOp7ZN$
1r~lh#_8
l7s=b4}c
} k 5"3*
Ka_UVKwMro
G)# ,39P
/* R1Pnj
**SiteInfoBean.java S_bay8L1
*/ +=k?Dp[
package NetFox; =oQzL
2jhVmK
^OBaVb
public class SiteInfoBean { W77JXD93
#eUfwd6.Y
~5!ukGK_
private String sSiteURL; //Site's URL pK'WJ 72U
private String sFilePath; //Saved File's Path EW5S%Y
private String sFileName; //Saved File's Name b,Z&P|
private int nSplitter; //Count of Splited Downloading File ='VIbE@qC
t*qA.xc6
vhL&az
public SiteInfoBean() ^F"*;8$
{//nSplitter的缺省值为5 "L8V!M_e
//default value of nSplitter is 5 awkVjyqX
this("","","",5); izC>-
} LpmspIPvf
9d{W/t?NH
=k$d8g ez
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q%eBm_r;
{ ^1~/FU
sSiteURL= sURL; pM46I"
sFilePath = sPath; !r LHPg
sFileName = sName; Hzj*X}X#K
this.nSplitter = nSpiltter; $AXz/fGV
%x927I>
O]Kb~jkd
} }TF<C!]
6U&Uyd)
z!3Z^d`
public String getSSiteURL() rmabm\QY
{ %'=oMbi>i4
return sSiteURL; Qy70/on9
} VuPET
dt \O7Rjw8
<oXsn.'\
public void setSSiteURL(String value) 6sZRR{'
{ xc/|#TC8?
sSiteURL = value; <GNOT"z
} l?R_wu,Q
0l:5hD,)F
eXOFAd]>u
public String getSFilePath() X~DXx/9
{ P9>C!0 -x
return sFilePath; 6AwnmGL(;;
} w-#0k.T
Hug{9Hr3.
7S1!|*/ I
public void setSFilePath(String value) kyjH~mK4
{ _bd#C
sFilePath = value; DA wzXsx
} }2r08,m
?Tl@e
xw-q)u
public String getSFileName() &*yve}su
{ L_.}z)S[\
return sFileName; u!-eP7;7
} 0*AlLwO
ua[\npz5
V8sY7QK=
public void setSFileName(String value) q@sH@-z4]
{ X3-1)|g !z
sFileName = value; nB]Q^~jX
} X,N@`
\1MDCP9:
+,-rb
public int getNSplitter() dXDD/8E
{ <R(2 9QN
return nSplitter; (s3%1OC[
} Ck:J
FO5SXwx
5`uS<[vA
public void setNSplitter(int nCount) JdRs=#X
{ >'jM8=o*Ax
nSplitter = nCount; CS{9|FNz
} h|H;ZC(B
} GMNb;D(>K
E\zhxiI
L[bGO|O
/* BJE <~"
**Utility.java U .Od
*/ bGJUu#
package NetFox; 5QSmim
1P[Lz!C
3aqmK.`H
public class Utility { &f yFUg
LF~#4)B
sZH7EK
public Utility() ~"mZ0E
{ II8nz[s
9y4rw]4zI
(=/F=,w
} v wyDY%B"n
:=Q|gRTL*
//线程睡眠 +)@>60y
public static void sleep(int nSecond) 9y5\4&v
{ ]xG8vy
try{ yq}{6IyZ^
Thread.sleep(nSecond); RI(uG-Y
} ~ YK<T+
catch(Exception e) `Z/IW
{ 9CNHjs+-}s
e.printStackTrace (); K_5&_P1
} IebS~N E
} 5);#\&B
JqUVGEg
//日志 e%U*~{m+
public static void log(String sMsg) .vv*bx
{ 8j'*IRj*q
System.err.println(sMsg); 752wK|o0|;
} LU{Z
]~^/w}(K
is(!_Iv
public static void log(int sMsg) =5ih,>>g
{ 4I-p/&Q
System.err.println(sMsg); //Gvk|O1
} Oi0;.<kX
} JY2 F-0t)
$3TTHS o
i .N1Cvp&
/* !_9$[Oq~
**TestMethod.java h)rf6*hw
*/ i6d$/yP"
package NetFox; lX*;KHT)
swlWe}1
,}tdfkZFYl
public class TestMethod { o"FiM5L^.
Xa@wN/"F
(UF!Zb]{
public TestMethod() sAoM=n}!
{ ///xx/weblogic60b2_win.exe zy[=OX+
try{ RfBb{?PP)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |y%].y)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u-{l,p_H
SiteFileFetch fileFetch = new SiteFileFetch(bean); ql~{`qoD~
fileFetch.start(); pV6HQ:y1
} 4Aew )
catch(Exception e){e.printStackTrace ();} wzPw;xuG
DOVX$N$3
oKi1=d+T
} el?V2v[
}+4Bf+u:
&a_kJ)J
public static void main(String[] args) m@.{zW7bO
{ @$P!#z
new TestMethod(); $Je"z]cy-
} 6I.mc
} n[Iu!v\/*
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