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)); <4ccTl
} FIL?nkYEO
for(int i=0;i<nEndPos.length-1;i++) 0M7Or)qN
{ Dq/_^a/1
nEndPos = nStartPos[i+1]; k@L},Td
} qsOA(+ZP
nEndPos[nEndPos.length-1] = nFileLength; Se.\wkl#Y
} cY8XA6
} EiQX*v
J3fk3d`2
,m;S-Im_Xr
//启动子线程 29("gB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /2N'SOX
for(int i=0;i<nStartPos.length;i++) ]VtVw^ir
{ hiq7e*Nsb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GqMa|8j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $M{MOehZ
nStartPos,nEndPos,i); /j/,@,lw7z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t2skg
fileSplitterFetch.start(); $\M<gW6
} U_i%@{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ir&rTGFN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8mjPa^A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Yv<'QC
nEndPos = " + nFileLength); =lT~
// fileSplitterFetch[nPos.length-1].start(); $mdmuUIy-3
O'm><a>8
Fa<>2KkOr
//等待子线程结束 4<}!+X7m
//int count = 0; uu ahR
//是否结束while循环 /kV3[Rw+
boolean breakWhile = false; 1P4cBw%
BIGln`;,f
~puXZCatN
while(!bStop) KYE)#<V}@
{ aF*KY<w
write_nPos(); 8Na.H::cZ
Utility.sleep(500); \WS2g"(
breakWhile = true; .5L|(B=H
wcr3ugvT
loRT+u$&
for(int i=0;i<nStartPos.length;i++) q^!_jMN5
{ I(^pIe-
if(!fileSplitterFetch.bDownOver) A*+pGQ
{ h?_Cv*0q
breakWhile = false; F1_s%&
break; di.yh3N$
} }9:(l
} 44Dytpvg
if(breakWhile) I=aoP}_
break; LR:PSgy
y;Ez|MS
X,5}i5'!
//count++; ,+w9_Gy2H
//if(count>4) Z9 z!YaOL
// siteStop(); G5WQTMzf&
} HQp\0NC]
x[?N[>uw
@jL](Mq|]
System.err.println("文件下载结束！"); CdBpz/
} (vX) <Z !
catch(Exception e){e.printStackTrace ();} ^aG$9N<\
} oX=dJJE
T`?7z+2A
./]xn
//获得文件长度 H1GmC`\<[:
public long getFileSize() 6a*?m{
{ zA%YaekJ
int nFileLength = -1; ]ilQq~X
try{ jz,K>
URL url = new URL(siteInfoBean.getSSiteURL()); 1NAGGr00
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s5bqS'%
httpConnection.setRequestProperty("User-Agent","NetFox"); --fRhN>
awXK9}.
sX@}4[)<&
int responseCode=httpConnection.getResponseCode(); gmUXh;aHc
if(responseCode>=400) 7vo8lnQ{
{ ` 0$i^,}
processErrorCode(responseCode); _sb~eB~<(
return -2; //-2 represent access is error >&DC[)28
} {MRXKnm;e
gt(^9t;
&k@\k<2Ia
String sHeader; <ni_78
T_)g/,5>
1[yy/v'q
for(int i=1;;i++) H#S`m
{ F?z:[1(:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KuRJo]
//Utility.log(in.readLine()); pG6?"*Fz;
sHeader=httpConnection.getHeaderFieldKey(i); Vp7d
if(sHeader!=null) uTdx`>M,O
{ 7|HIl=
if(sHeader.equals("Content-Length")) DPlDuUOd
{ yV~TfTJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D6dliU?k
break; 5tI#UBha
} |KR8=-!7
} y>#_LhTX-
else bUsX~R-
break; /F$E)qN7n
} iT;Ld $!{f
} =@nE:uto]
catch(IOException e){e.printStackTrace ();} %aI,K0\
catch(Exception e){e.printStackTrace ();} t~H0Qeb[v=
n$lVmQ6
=H`yzGt
Utility.log(nFileLength); ?y]R /?
m-qu<4A/U|
]v/pMg#-
return nFileLength; 2,Aw6h;
} h<Ct[46,S
67;6nXG0K
[_KV;qS%/
//保存下载信息（文件指针位置） =van<l4b#n
private void write_nPos() Ge @qvP_
{ f|=u{6
try{ PqIskv+
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,1g_{dMx
output.writeInt(nStartPos.length); !PA><F
for(int i=0;i<nStartPos.length;i++) 7|o!v);uR
{ $|g ;
// output.writeLong(nPos); cV"Ov@_.k
output.writeLong(fileSplitterFetch.nStartPos); `T+w5ONn
output.writeLong(fileSplitterFetch.nEndPos); GKbbwT0T|
} M}j[{wW3
output.close(); rq^%)tR
} ^D]J68)#a
catch(IOException e){e.printStackTrace ();} <$@I*xk[
catch(Exception e){e.printStackTrace ();} w=CzPNRHH!
} @U4hq7xzV2
}VRl L>HAC
+?W4ac1
//读取保存的下载信息（文件指针位置） lu6iU
private void read_nPos() c:52pYf+
{ '=O1n H<
try{ }a/z.&x]V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q lA?dXQ
int nCount = input.readInt(); IBvn q8\
nStartPos = new long[nCount]; &]Uo>Gb3!q
nEndPos = new long[nCount]; -Bl^TT
for(int i=0;i<nStartPos.length;i++) :5['V#(o
{ C=|8C70[%N
nStartPos = input.readLong(); kt0xR)gU
nEndPos = input.readLong(); $Mj\ 3
} V%)Tu{L
input.close(); *7-rm
} >_xuXEslUz
catch(IOException e){e.printStackTrace ();} g1?9ge1
catch(Exception e){e.printStackTrace ();} /D1Lh_,2
} g~b$WV%
'l`prp3
tHo|8c~[
private void processErrorCode(int nErrorCode) ;BqCjS%`N
{ \@yJbhk
System.err.println("Error Code : " + nErrorCode); M|j=J{r
} u]7wd3(
\{]y(GT
\K~wsu/?`
//停止文件下载 V@T(%6<|
public void siteStop() Cc*R3vHM6
{ _'ebXrbZB
bStop = true; e8T"d%f?
for(int i=0;i<nStartPos.length;i++) yci}#,nb
fileSplitterFetch.splitterStop(); Ef?hkq7X<
hdi0YL
|0oaEd^*}
} \y:48zd
} p}h.2)PO
//负责部分文件的抓取 [FrLxU
**FileSplitterFetch.java mNacLkh[
*/ Dw7Xy}I/
package NetFox; d@1^U9sf
^r.CUhx)
b}ya9tCl;
import java.io.*; b=xn(HE8|
import java.net.*; G"E_4YkJ
!&hqj$>-}
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public class FileSplitterFetch extends Thread { GVJ||0D
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MjQju@
String sURL; //File URL {4,],0bjx/
long nStartPos; //File Snippet Start Position _p%n%Oce
long nEndPos; //File Snippet End Position d?J&mLQ6
int nThreadID; //Thread's ID Y 0Fq-H
boolean bDownOver = false; //Downing is over Vc;[0iB
boolean bStop = false; //Stop identical =t)qy5
FileAccessI fileAccessI = null; //File Access interface &e:+;7
;*<R~HJt
1S!}su,uH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RU4X#gP4Vh
{ Jj+Q2D:
this.sURL = sURL; eBnx$
this.nStartPos = nStart; S<Gm*$[7
this.nEndPos = nEnd; l#1#3F
nThreadID = id; |r Aot2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QwWd"Of
} &`v?oN9$
{~&Q"8 }G
r>peKo[X(
public void run() jK]1X8
{ rf%lhBv
while(nStartPos < nEndPos && !bStop) =dDPQZEin
{ 4k@n5JNa
Fy Ih\
_8u TK%|
try{ <JWU@A-.y
URL url = new URL(sURL); <n]PD;.4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eN,9N]K
httpConnection.setRequestProperty("User-Agent","NetFox"); HS{Vohy>
String sProperty = "bytes="+nStartPos+"-"; ~W8Xg)
httpConnection.setRequestProperty("RANGE",sProperty); |*NZ^6`@
Utility.log(sProperty); xt?-X%oY8
O%\cRn8m
=;uMrb4
InputStream input = httpConnection.getInputStream(); 4-x<^ ev=
//logResponseHead(httpConnection); yj&GJuNb~
2@6@|jRG
MmjZq
byte[] b = new byte[1024]; WSH[*jMA
int nRead; vnvpb! @Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dE_Xd:>
{ F&czD;F
nStartPos += fileAccessI.write(b,0,nRead); T{C;bf:Q
//if(nThreadID == 1) :,JaOn'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }OAU5P!rp
} b`#YJpA
O68-G
tjx8UgSi
Utility.log("Thread " + nThreadID + " is over!"); *{w0=J[15
bDownOver = true; <C'_:&M
//nPos = fileAccessI.write (b,0,nRead); IHO*%3mA/
} 34u[#O{2
catch(Exception e){e.printStackTrace ();} W|>jj$/o
} "frZ%mv
} +ausm!~6
`;6M|5G
fI)XV7,X
//打印回应的头信息 c]|vg=W
public void logResponseHead(HttpURLConnection con) vzg^tJ
{ ~rBFP)
for(int i=1;;i++) DPzW,aIgv
{ 7_1 Iadb
String header=con.getHeaderFieldKey(i); k-|g
if(header!=null) CXrOb+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p2gdAJ
Utility.log(header+" : "+con.getHeaderField(header)); 8/aJ4w[A
else gLv+L]BnhH
break; kT@ITA22
} ]XEyG7D
} HqWWWCWal
6LDZ|K@
CqnHh@]nu
public void splitterStop() :b44LXKCP
{ $#hU_vr
bStop = true; m0bxVV^DK!
} 3HrG^/
oWY3dc
#EzhtuHxn
} 9A.NM+u7
DS(>R!bb
/+92DV
/* ,"`20.Lv
**FileAccess.java n{4iW_/D
*//文件访问(定位，写) %Y ZCdS
package NetFox; K:U=Y$x
import java.io.*; "^$Ht`p[
9Ad%~qciY
YdCl
public class FileAccessI implements Serializable{ ~RbVcB#
|-=-/u1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y ~ K8
RandomAccessFile oSavedFile; s1_Y~<yX
long nPos; bW W!,-|R
g&g:HH:
i 7]o[
public FileAccessI() throws IOException R9A:"sJ
{ y05!-G:Y\
this("",0); .vKgiIC:
} K7&]|^M9
Ja3#W K
i`@cVYsL
public FileAccessI(String sName,long nPos) throws IOException oqwW
{ hD5@PeLh
oSavedFile = new RandomAccessFile(sName,"rw"); _W(xO |,M
this.nPos = nPos; z!6_u@^-
oSavedFile.seek(nPos); bnfeZR1m_
} ZiR}S
LBG`DYR@
"T5jz#H#/
public synchronized int write(byte[] b,int nStart,int nLen) bq7+l4CGTv
{ A/=cGE
int n = -1; E4Q`)6]0
try{ i}LQ}35@
oSavedFile.write(b,nStart,nLen); vltE2mb
n = nLen; RbUir185Y
} ek)rsxf1A
catch(IOException e) w31O~Ve
{ qsp3G7\'=
e.printStackTrace (); &H# l*
} A(&\wd
TQeIAy
%GjG.11V,_
return n; wOL%otEf
} `GqF/?i
umPnw
ZOqA8#\
} P:6K
tz65Tn_M
Pq~#SxA~
/* * g+v*q X
**SiteInfoBean.java oa+'.b~
*/ n\Is}Czl
package NetFox; X ([^i;mr
j*8Ze!^
&z3_N
public class SiteInfoBean { FBP #_"z
LL:N/1ysG
Q +hOW-
private String sSiteURL; //Site's URL zk70D_}L
private String sFilePath; //Saved File's Path ~xam ;]2
private String sFileName; //Saved File's Name *W2] Kxx*
private int nSplitter; //Count of Splited Downloading File aU +uPP
n"iaE
z1RHdu0;z
public SiteInfoBean() jY9tq[~/
{//nSplitter的缺省值为5 7 HL Uk3
//default value of nSplitter is 5 6;Izw$X
this("","","",5); :1'1n
} ,EH-Sf2Cb
aG"
5-a^Frmg#"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jz'%(6#'gW
{ /q]fG
sSiteURL= sURL; kVWrZ>McK
sFilePath = sPath; %LdBO1D0
sFileName = sName; 3Qv9=q|[b
this.nSplitter = nSpiltter; K:4G(?w
z,qNuv"W
4wS!g10}
} /$8& r
D_f:D^
M;-FW5O't
public String getSSiteURL() T/L\|_:'
{ Hb!A\;>
return sSiteURL; BaCzN;)
} 3wgZDF38
1{xkAy0
>]bS"S
public void setSSiteURL(String value) }q/[\3
{ U$ZbBVa`~
sSiteURL = value; 2JHF*zvO-
} kx0w?A8-
f`J[u!Ja
&M\qVL%w
public String getSFilePath() |Pse=_i
{ Fw#wVs)@:
return sFilePath; n u>6UjV
} '(:R-u!pp
'xOH~RlE
y3 S T"U
public void setSFilePath(String value) #b=*hi`E
{ vnsMh
sFilePath = value; p_sqw~)^%
} BI6`@}%7>
$)O\i^T
,S3uY6,
public String getSFileName() 7mS_Cz+cB
{ `MMZR=LA
return sFileName; u7u1lx>S
} 2f0_Xw_V_
=~j S
-F-,Gcos
public void setSFileName(String value) %aJ8wYj*
{ O6!:Qd
sFileName = value; 2Y9@[
} t4,(W`
=hKu85
A `=.F
public int getNSplitter() ^d/,9L\U
{ `l}r&z(8
return nSplitter; !%yd'"6Dl
} jowR!rqf
/\uW[mt
=^3B&qQNq
public void setNSplitter(int nCount) HFf9^
{ ZGWZ2>k
nSplitter = nCount; 4}=Z+tDu>
} vn=0=(
} RjQdlr6*
q0]Z` <w
4EEXt<c.
/* /H[!v:U
**Utility.java EY 9N{
*/ +QVe -
package NetFox; -qndBS
%L;'C v
AVv8Hhd
public class Utility { Ej64^*
~C2[5r{So
e$@azi1
public Utility() ) bGzsb1\
{ p^QB^HEV
S~LTLv:>
% 2lcc"'
} |#!P!p}
~,.}@XlgT.
//线程睡眠 @=1kr ^i
public static void sleep(int nSecond) 0FD+iID
{ KFMEY\6\h
try{ Syj7K*,%bZ
Thread.sleep(nSecond); (t)a u
} WH^rM`9
catch(Exception e) UN*XLHio
{ ~'l.g^p bv
e.printStackTrace (); F[SYs/M
} 0if~qGm=!
} p94 w0_m@|
C6C7*ks
//日志 _mw(~r8R
public static void log(String sMsg) KzC`*U[
{ 4h[^!up.7
System.err.println(sMsg); (7g1eEK%
} "xV9$m>
J<{@D9r9<~
<ZM8*bqi
public static void log(int sMsg) M(2c{TT
{ a~F`{(Q2
System.err.println(sMsg); n3kYVAgF
} 'j+J?Y^
} `n!<h,S'2
jci'q=Vpu
A,T3%TE
/* )'RLK4l
**TestMethod.java v&EHp{8Qd
*/ &\0`\#R
package NetFox; `8 Dgk}
Uv06f+P(
b)A$lP%`
public class TestMethod { IRZ?'Im
f&S,l3H<
hD>O LoO
public TestMethod() *zy0,{bl
{ ///xx/weblogic60b2_win.exe nO~TW
try{ "(+>#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q b5AQf30
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #n'tpp~O
SiteFileFetch fileFetch = new SiteFileFetch(bean); By8C-jD
fileFetch.start(); @GYM4T
} GJA3
catch(Exception e){e.printStackTrace ();} #GYCU!
u=I>DEe@c
sYt8NsQ
} W)F2X0D>
mb*L'y2r
1_7}B4
public static void main(String[] args) $o`N%]
{ Zjt3U;Y
new TestMethod(); _wg6}3
} 1x]U&{do
} oUm"qt_
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