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)); gf4Hq&Rf
} qvhG^b0h
for(int i=0;i<nEndPos.length-1;i++) Ep')@7^n
{ bun_R-
nEndPos = nStartPos[i+1]; /6\uBy"Xt
} ?G]yU
nEndPos[nEndPos.length-1] = nFileLength; #,})N*7
} ]2iIk=r$
} JPj/+f
%.\+j,G7
\X]I: 0^j
//启动子线程 p#rqe<Ua
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >!o!rs
for(int i=0;i<nStartPos.length;i++) O]F(vHK\
{ +x4*T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4ISIg\:c*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [kgCB7.V
nStartPos,nEndPos,i); H&k&mRi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,MHF
fileSplitterFetch.start(); o`'4EVw*
} I\j-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w&]$!g4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `7V1 F.\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >^<;;8Xh
nEndPos = " + nFileLength); #Wb4*
// fileSplitterFetch[nPos.length-1].start(); ~52'iI)Mw
>:FmAey
v"Ryg]^_
//等待子线程结束 \]\GDpu[
//int count = 0; !Ow M-t
//是否结束while循环 X;vUz
boolean breakWhile = false; 6vJS"+ <
[+}0K{(O=
XJq]l6a:
while(!bStop) 4`RZ&w;1H2
{ -ntQqHs
write_nPos(); vJx( lU`Y
Utility.sleep(500); (gcy3BX;
breakWhile = true; {\LLiU}MJC
?\X9Ei
mU||(;I
for(int i=0;i<nStartPos.length;i++) f&] !;)
{ M$6;&T
if(!fileSplitterFetch.bDownOver) B LZ<"npn
{ _Vc4F_
breakWhile = false; g(Oor6Pp
break; ;MlPP)*k
} b!"FM/%
} !)}z{,Jx
if(breakWhile) k@[[vj|W
break; p2+K-/}ApP
i.-2 w6
CWd &
//count++; O%&N6U
//if(count>4) $"0`2C
// siteStop(); 1$m{)Io2(
} 2) 2:KX
UvqnNA
Zl]@;*u
System.err.println("文件下载结束！"); 6_tl_O7
} F2)KAIl
catch(Exception e){e.printStackTrace ();} qB`%+<)C
} -|=)
-`t9@1P> =
sdgI ,
//获得文件长度 Az>r}*FGr
public long getFileSize() Mdu\ci)lr
{ ,.<c|5R
int nFileLength = -1; BcQw-<veu
try{ jpMMnEVj6P
URL url = new URL(siteInfoBean.getSSiteURL()); 7+6I~&x!Lz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7WmY:g#s
httpConnection.setRequestProperty("User-Agent","NetFox"); s]D1s%Mx
+p]@b
'S=eW_ 0/
int responseCode=httpConnection.getResponseCode(); 6&2{V? W3
if(responseCode>=400) _C'VC#Sy
{ ]/[@.
processErrorCode(responseCode); /}CAd
return -2; //-2 represent access is error *ck'vV'@
} XuU>.T$]c
.n?i'8
D@@"w+
String sHeader; J10&iCr{r*
iqsR]mab
mQK3YoC)
for(int i=1;;i++) ,E+\SBQS_
{ C]na4yE8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FEV Ya#S
//Utility.log(in.readLine()); lr -+|>M)
sHeader=httpConnection.getHeaderFieldKey(i); (8/&
if(sHeader!=null) `bd9N!K
{ PevT`\>
if(sHeader.equals("Content-Length")) VZ9`Kbu
{ VQ+G.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _m%Ab3iT~
break; 9.6ni1a'
} x Y}.mP
} gN<J0c)
else Scmew
break; ,z+n@sUR:
} #210 Yp#
} ^Q!A4qOQ
catch(IOException e){e.printStackTrace ();} &u(pBr8B
catch(Exception e){e.printStackTrace ();} &nY#GHB
O}6*9Xy
oS_YQOoD
Utility.log(nFileLength); @?t+O'&
&.Yu%=}
#X?E#^6?E
return nFileLength; ~D/1U)kt
} b~TTz`HZ
A[:(#iR5-E
~cfvL*~5
//保存下载信息（文件指针位置） \GGyz{i
private void write_nPos() SUsdX[byb
{ _0Y?(}
try{ #aKUD
output = new DataOutputStream(new FileOutputStream(tmpFile)); S*WLb/R2
output.writeInt(nStartPos.length); x3nUKQtk:8
for(int i=0;i<nStartPos.length;i++) 81)i>]
{ (>*L-&-
// output.writeLong(nPos); &uf|Le4
output.writeLong(fileSplitterFetch.nStartPos); =}SLQdT
output.writeLong(fileSplitterFetch.nEndPos); Hig.` P
} g}*p(Tp9:
output.close(); )k4&S{=
} iN5[x{^t
catch(IOException e){e.printStackTrace ();} uME_/S uO
catch(Exception e){e.printStackTrace ();} Z07n>|WF-
} KJt6d`ZN
(:}}p}u
xb&,9Lxd|
//读取保存的下载信息（文件指针位置） 5BM6Pnle
private void read_nPos() mdcsL~R
{ J{nA ?[
try{ (/!zHq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !d95gq<=>
int nCount = input.readInt(); @q{.shqo
nStartPos = new long[nCount]; nu[["f~
nEndPos = new long[nCount]; GB)< 5I
for(int i=0;i<nStartPos.length;i++) w)/~Gn676
{ y%<CkgZS
nStartPos = input.readLong(); NA#,q 8
nEndPos = input.readLong(); ZRFHs>0
} :fnK`RnaQ
input.close(); }8`>n4
} *mW2vJ/B
catch(IOException e){e.printStackTrace ();} vxrqUjK7
catch(Exception e){e.printStackTrace ();} 0sF|Y%N
} LQ||7>{eX
gYmO4/c,
[?2,(X0yh1
private void processErrorCode(int nErrorCode) KfQR(e9n
{ +Y>oNX1KN
System.err.println("Error Code : " + nErrorCode); ]y"=/Nu-Ja
} U~oGg$
[Y^h)k{-$
}gd'pgN"t
//停止文件下载 KNOVb=#f_
public void siteStop() #jPn7
{ caV DV
bStop = true; cV4Y= &
for(int i=0;i<nStartPos.length;i++) ^RYq !l$
fileSplitterFetch.splitterStop(); P4 #j;k4P
KD--w(4
`A8ErfA
} sR)jZpmC(
} 9d!mGnl
//负责部分文件的抓取 nt%p@e!,
**FileSplitterFetch.java Hv%$6,/*v
*/ V$dhiP z
package NetFox; Epm8S}6K
#IU^(W
B_XX)y%V
import java.io.*; 6wZ)GLW[
import java.net.*; =RQI5nHdw
$\PU Y8
\(r$f!`
public class FileSplitterFetch extends Thread { F#.ph?W
'@HCwEuz
*<X*)A{C
String sURL; //File URL |n~,{=
long nStartPos; //File Snippet Start Position j@{dsS:6
long nEndPos; //File Snippet End Position .-Dc%ap]
int nThreadID; //Thread's ID al7D3J
boolean bDownOver = false; //Downing is over >qd=lm <,
boolean bStop = false; //Stop identical {P)O#
FileAccessI fileAccessI = null; //File Access interface xT!<x({
QH?sx k2
Bi>]s%zp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s5)y%,E
{ ,,lR\!>8
this.sURL = sURL; "CZv5)
this.nStartPos = nStart; M;YJpi
this.nEndPos = nEnd; }^^c/w_
nThreadID = id; flOXV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _z9~\N/@[
} ^1_CS*
[\&2&
]0W64cuT
public void run() j-ob7(v)*]
{ $xjfW/k?M
while(nStartPos < nEndPos && !bStop) ]ZNFrpq
{ Q8$;##hzt
{uJ"%
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try{ E0+~c1P-
URL url = new URL(sURL); W{~ y< `D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s^Xs*T@~h
httpConnection.setRequestProperty("User-Agent","NetFox"); YGRb|P-
String sProperty = "bytes="+nStartPos+"-"; q$Ms7`a
httpConnection.setRequestProperty("RANGE",sProperty); 0f_A"K
Utility.log(sProperty); kO$n0y5e
ab]Q1kD
hFxT@I~
InputStream input = httpConnection.getInputStream(); <`wOy[e
//logResponseHead(httpConnection); @a,=ApS"
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m!=5Q S3Z
byte[] b = new byte[1024]; y9w,Su2
int nRead; }w8yYI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zL'S5'<F|
{ N>1d]DrQR
nStartPos += fileAccessI.write(b,0,nRead); ef/43+F^x
//if(nThreadID == 1) >Psq" Xj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a2/Mf
} zS h9`F
*zW]IQ'A
Ex skd}
Utility.log("Thread " + nThreadID + " is over!"); .L]5,#2([
bDownOver = true; [(&aVHUj
//nPos = fileAccessI.write (b,0,nRead); qk(bA/+e
} !!w(`kmn1
catch(Exception e){e.printStackTrace ();} 9vSKIq
} /XU=l0u
} bW=3X-)
gyhy0
dczSW]%
//打印回应的头信息 ]Tg@wMgI
public void logResponseHead(HttpURLConnection con) 2 )3oX
{ ,t:P
for(int i=1;;i++) Ge7B%p8
{ W1Ye+vg/s
String header=con.getHeaderFieldKey(i); =E^/gc%X
if(header!=null) I5`>XfO)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Wh~,?}laj
Utility.log(header+" : "+con.getHeaderField(header)); owb+,Gk(
else -Q&@P3x
break; S4-jFD)U
} 0rm(i*Q
} o[i*i<jv-
5%}!z~8Y4
`(=?k[48
public void splitterStop() F^S]7{
{ 69apTx
bStop = true; ck3+A/ !z
} 'GiN^Y9dcc
.w'b%M
-=5~-72~
} 6NHP/bj<1V
a'.7)f[g}
\fuz`fK:
/* 2)T;N`tNw
**FileAccess.java l-S0Gn/'X
*//文件访问(定位，写) ~*<`PDO?
package NetFox; 9Oo`4
import java.io.*; GlRjbNW?Q
'cQ,;y
lyyf&?2
public class FileAccessI implements Serializable{ \7pEn
0CK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *c&OAL]
RandomAccessFile oSavedFile; LZ.Xcy
long nPos; A1`6+8}o;b
lNtxM"G&
1i_%1Oip
public FileAccessI() throws IOException 3la`S$c
{ V{w &RJ
this("",0); )Q>Ao.
} iA[o;D#
@+Sr~:K
UUb0[oy
public FileAccessI(String sName,long nPos) throws IOException |5X59! JL
{ xXa4t4gR
oSavedFile = new RandomAccessFile(sName,"rw"); "*N#-=MJF
this.nPos = nPos; b{{ H@LTW
oSavedFile.seek(nPos); 56.JBBZZ
} P1B=fgT
>VQLC&u(
svb7-.!
public synchronized int write(byte[] b,int nStart,int nLen) u86PTp+
{ NGkxg:
int n = -1; =&qH%S6
try{ >5"e<mwD7d
oSavedFile.write(b,nStart,nLen); +"bi]^\z
n = nLen; Cc,V ]
} kE8s])Z,+
catch(IOException e) UK1)U)*+
{ -3azA7tzz
e.printStackTrace (); /!A"[Tyt
} $!y^t$u$@
JYA>Q&
4 2DMmwB
return n; u/-EVCHr y
} _nEVmz!zg
;134$7!Y
)pT5"{
} ;aX?K/
\%.oi@A
jYFmL_{
/* t u{~:Z(
**SiteInfoBean.java ?!/8~'xA6
*/ =Y6W Qf
package NetFox; '5[(QM5Gi&
47Bg[
+PI}$c-|`
public class SiteInfoBean { OVU)t]
dv3u<XM~
W*#5Sk
private String sSiteURL; //Site's URL Ip=QtNW3\
private String sFilePath; //Saved File's Path _z{9V7n4
private String sFileName; //Saved File's Name q(^iT~}
private int nSplitter; //Count of Splited Downloading File _KxR~k^
wvxz:~M
9p3~WA/M@
public SiteInfoBean() g1"ZpD
{//nSplitter的缺省值为5 zwJ&K;"y(
//default value of nSplitter is 5 un -h%-e|
this("","","",5); Ql l{;A
} 5(hv|t/a
v1X[/\;U
T4"D&~3 3q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ak('4j!*}^
{ [u2t1^#Ol
sSiteURL= sURL; NCG;`B`i
sFilePath = sPath; 92A9gY
sFileName = sName; 8wOscL f:
this.nSplitter = nSpiltter; bHE.EBZ
Y)1J8kq_
qGEp 6b H
} a%si:_
ty rP[y
-WF((s;<#
public String getSSiteURL() /V/NL#(R
{ |3!)
return sSiteURL; ~LV]cX2J(
} >dm9YfQ
Q1x&Zm1v
Lw_|o[I}
public void setSSiteURL(String value) " M?dU^U^
{ udA@9a^;
sSiteURL = value; 4 l-UrnZ
} Tq?Ai_
qTdwi?j_
ZAN~TG<n
public String getSFilePath() >(.|oT\Tb
{ =#y;J(>~|
return sFilePath; PQSmBTs.
} KA?%1s(kJ
LPu*Lkx
QSa#}vCp*
public void setSFilePath(String value) R2-F@_
{ 3e1-w$z&S
sFilePath = value; Uuu2wz3O0
} :Hm'o}
Xo~q}(ze^
oe 6-F)+
public String getSFileName() QkD ~
{ 0!0e$!8l
return sFileName; /(hTk&
} ,f:K)^yD
!3k-' ),z&
{4Kvr4)4
public void setSFileName(String value) )lS04|s
{ `NgQ>KV!
sFileName = value; _LC*_LT_
} v G\J8s
5=|h~/.k
7I"~a<f0X`
public int getNSplitter() 5o>`7(t`
{ Z.Z;p/4F
return nSplitter; 6LGl]jHf
} !ae?EJm"
,&S0/j
fK+E5~vQ
public void setNSplitter(int nCount) %,02i@Fc
{ `:V'E>B
nSplitter = nCount; :dULsl$Nz
} 6?<lS.s
} Y!_c/!Tx
O$m &!J
GAYn*'<
/* *#Ia8^z=p
**Utility.java ZlMT) ~fM&
*/ n~|?)EL
package NetFox; 2 A!*8w
;NdH]a{
}k%6X@
public class Utility { <Y?Z&rNb
mR@d4(:J?
-#T%*
public Utility() d!R+-Fp
{ ZZo<0kDk
jF}kV%E
g%S/)R,,ct
} 7:uz{xPK6
a4~B
//线程睡眠 1Xm>nF~
public static void sleep(int nSecond) 0'pB7^y
{ ]7W!f 2@
try{ DAWF =p]
Thread.sleep(nSecond); q 9xA.*
} ^#Q-?O
catch(Exception e) V^[&4
{ (W:@v&p
e.printStackTrace (); $RYGAh
} }l$zZ>.\H
} r.#r!.6 q
r1%{\<
//日志 bs)wxU`Q*
public static void log(String sMsg) Tt~[hC h
{ dB4ifeT]
System.err.println(sMsg); -A w]b} #v
} rmkBp_i{|
~<VxtcEBz
9Q s5e
public static void log(int sMsg) Bx|W#:3e
{ ,Owk;MV@
System.err.println(sMsg); OH2IO
} BX[IWP\%
} 1%B9xLq
N}B&(dJ
#9DJk,SP
/* hui #<2{
**TestMethod.java n)q8y0if
*/ 0:[A4S`X
package NetFox; L QV@]z&
#1'q'f:7&
(b#M4ho*f
public class TestMethod { }'x)e
Z!|r>
N^oP,^+U
public TestMethod() HLPRTta.
{ ///xx/weblogic60b2_win.exe %pjeA[-m#
try{ IL.bwtpQD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kj @<$ChZw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "*X\'LPs=
SiteFileFetch fileFetch = new SiteFileFetch(bean); g{}<ptx]
fileFetch.start(); 8el6z2
} E<3xv;v8r
catch(Exception e){e.printStackTrace ();} `0]N#G T
GZrN,M
hfY/)-60o
} Fn`Zw:vp6
h]&
Qv~@
public static void main(String[] args) -9{N7H
{ /fT"WaTEK
new TestMethod(); 7!jb
} |Ol29C$@|
} ^|Fy!kp
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