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)); )sNtwSl^
} "t_]Qu6
for(int i=0;i<nEndPos.length-1;i++) gn(n</\/O
{ ITbl%q
nEndPos = nStartPos[i+1]; 2? !b!
} 8KoPaq
nEndPos[nEndPos.length-1] = nFileLength; =~aJ]T}(
} O4$: xjs
} 2! wz#EC
I/^Lr_\
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//启动子线程 ,9+@\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _'j>xK
for(int i=0;i<nStartPos.length;i++) G0*$&G0nb
{ C!Tl?>Tt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e[e2X<&0RT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Uc9Uj
nStartPos,nEndPos,i); I|R9@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]i$CE|~
fileSplitterFetch.start(); UJ6WrO5#kB
} 'Z&A5\~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t5e(9Yhj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r2&{R!Fj`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Bq@G@Qi
nEndPos = " + nFileLength); $\P!P.
// fileSplitterFetch[nPos.length-1].start(); has5"Bb
{ZfTUt)-P
g" M1HxlV
//等待子线程结束 &$+yXN
//int count = 0; eN jC.w9
//是否结束while循环 TUk1h\.q
boolean breakWhile = false; 7x1jpQ-
\<z{@
Y@.:U*
while(!bStop) 3cOXtDV YT
{ 8o4 vA,
write_nPos(); ^AEg?[q
Utility.sleep(500); ].1R~7b
breakWhile = true; fitm*
lv8tS-
+"d{P,[3J
for(int i=0;i<nStartPos.length;i++) ("9)=x*5
{ 'vCFT(C-
if(!fileSplitterFetch.bDownOver) N:&Gv'`
{ n ~ =]/
breakWhile = false; xwz2N5
break; cPtP?)38.
} L:%h]-
} %F{@DN`
if(breakWhile) ;xj^*b
break; ~w!<J-z)
m$$U%=r>@
5SK.R;mn
//count++; {cG&l:-r
//if(count>4) ZB%7Sr0
// siteStop(); HF0J>Clq
} rgOB0[
xEZvCwsb
fHe3 :a5+W
System.err.println("文件下载结束！"); Q4Cw{2r
} t/y0gr tm6
catch(Exception e){e.printStackTrace ();} 58=fT1 B
} ;H}?8L
Q+#, VuM
rVZkG,Q
//获得文件长度 X\flx~
public long getFileSize() ^IC|3sr
{ xe_c`%_
int nFileLength = -1; ^#_@Kq%th
try{ n.Ekpq\
URL url = new URL(siteInfoBean.getSSiteURL()); i5:fn@&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4S+P]U*jW
httpConnection.setRequestProperty("User-Agent","NetFox"); LnM+,cBz
g9 g &]
E?%rmdyhL!
int responseCode=httpConnection.getResponseCode(); C !uwD
if(responseCode>=400) rw58bkh6
{ B6|=kl2C
processErrorCode(responseCode); hXZk$a'
return -2; //-2 represent access is error tX6n~NJ$
} ]BX|G`CCc
.`iOWCS
0urQA_JC
String sHeader; ALPZc:
^|OxlfS
UDGVq S!,E
for(int i=1;;i++) F DXAe-|Q
{ qJrK?:O;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4fQ<A <2/
//Utility.log(in.readLine()); Z+FJ cvYx
sHeader=httpConnection.getHeaderFieldKey(i); ".~,(*
if(sHeader!=null) k${25*M!3
{ a$"3T
if(sHeader.equals("Content-Length")) E ekX|*
{ X`#vH8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <D!"<&N
break; V+-%$-w>
} CKy' 8I9
} g2BE-0,R
else 3hGYNlQ^
break; z'j4^Xz?%$
} RMDzPda.
} 9J$N5
catch(IOException e){e.printStackTrace ();} /Rf:Z.L
catch(Exception e){e.printStackTrace ();} 'de&9\
(gQP_Oa(
}k~ih?E^s
Utility.log(nFileLength); 3c}@_Yn
kq8.SvIb
YZMSiDv[e
return nFileLength; F}wy7s2i
} r roI
E{k$4
f; w\k7 #
//保存下载信息（文件指针位置） TD!--l*gL
private void write_nPos() 0*]n#+=
{ _Dr9 w&;<
try{ %68'+qz
output = new DataOutputStream(new FileOutputStream(tmpFile)); jmPnUn
output.writeInt(nStartPos.length); #oW"3L{,
for(int i=0;i<nStartPos.length;i++) ?I{L^j^#4
{ 9kHVWDf
// output.writeLong(nPos); >J*x` a3Q
output.writeLong(fileSplitterFetch.nStartPos); JlR$"GU
output.writeLong(fileSplitterFetch.nEndPos); >mJH@,F:
} +fS<YT
output.close(); !mHMFwvS
} 2*Zk^h=
catch(IOException e){e.printStackTrace ();} lonV_Xx
catch(Exception e){e.printStackTrace ();} 2,aH1Xbex
} BX\/Am11
>m]LV}">O
MH=7(15R
//读取保存的下载信息（文件指针位置） ^G|*=~_
private void read_nPos() <aztbq?
{ xt_:R~/[
try{ ;/:Sx/#s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zxa.x?:?n
int nCount = input.readInt(); 6b2UPI7m~
nStartPos = new long[nCount]; M]x>u@JH
nEndPos = new long[nCount]; b 7UJ
for(int i=0;i<nStartPos.length;i++) 6':iW~iI
{ eS`VI+=@0
nStartPos = input.readLong(); +yGQt3U
nEndPos = input.readLong(); '![oLy
} b)LT[>f
input.close(); /*K2i5&X
} p4`1^}f&Ie
catch(IOException e){e.printStackTrace ();} H_+n_r*
catch(Exception e){e.printStackTrace ();} wA) Hot
} EBj^4=b[
]Bhy=1
2u"lc'9v
private void processErrorCode(int nErrorCode) y0zMK4b
{ "6B7EH
System.err.println("Error Code : " + nErrorCode); g^AQBF
} h>N}M}8
XzUGlrp:Y#
]c.w+<
//停止文件下载 g@.$P>Bh
public void siteStop() U7r8FLl
{ Vwkvu&4
bStop = true; NGx3f3 9
for(int i=0;i<nStartPos.length;i++) 2]>O ZhS
fileSplitterFetch.splitterStop(); 5)[~ T2j!
\Wbmmd}8
T]#V
} zLI0RI.Pe
} ZnG.::&:
//负责部分文件的抓取 ^D yw(>9
**FileSplitterFetch.java )vp0X\3q`
*/ 'h>uR|
package NetFox; K/Q"Z*
SN{z)q
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import java.io.*; `Q]N]mK
import java.net.*; -YRIe<}E -
JF~i.+{h
/d`"WK,
public class FileSplitterFetch extends Thread { L@}PW)#
>lI7]hbIs
ho]:)!|VY
String sURL; //File URL 5]xuU.w'
long nStartPos; //File Snippet Start Position &C 9hT
long nEndPos; //File Snippet End Position =ily=j"hK
int nThreadID; //Thread's ID X>q`F;W
boolean bDownOver = false; //Downing is over rfXxg^
boolean bStop = false; //Stop identical sD|l}f
FileAccessI fileAccessI = null; //File Access interface sI ,!+
JA^o/%a^
\Mf>X\}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |s8N
{ O-iE0t
this.sURL = sURL; N& _~y|
this.nStartPos = nStart; hor7~u+
this.nEndPos = nEnd; =c8}^3L~7
nThreadID = id; (In{GA7;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k,h602(
} &L o TO+
} ueFy<F
[&x9<f6
public void run() QX,$JM3
{ /l$x}
while(nStartPos < nEndPos && !bStop) m</m9h8
{ ofvR0yV
t],a1I.gk
P_bB{~$4
try{ W!Tx%
URL url = new URL(sURL); $vn6%M[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rd <m:r
httpConnection.setRequestProperty("User-Agent","NetFox"); QcegT/vO
String sProperty = "bytes="+nStartPos+"-"; ffKgVQux
httpConnection.setRequestProperty("RANGE",sProperty); |vI*S5kn6A
Utility.log(sProperty); $l.*;h*
F^!D[:;jK
P.~UUS
InputStream input = httpConnection.getInputStream(); h~dQ5%
//logResponseHead(httpConnection); X>(1fra4
:X2_#qW#C
01kRe
byte[] b = new byte[1024]; ^2+Ex+
int nRead; F.s$Y+c!6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a~o<>H
{ U,GSWMI/K
nStartPos += fileAccessI.write(b,0,nRead); u6iW1,#
//if(nThreadID == 1) _H]\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !-I,Dh-A
} n ]%2Kx
e=amh
X><C#G
Utility.log("Thread " + nThreadID + " is over!"); ?0qVyK_1
bDownOver = true; %h.zkocM
//nPos = fileAccessI.write (b,0,nRead); Bfb~<rs[
} D%>Bj>xQD
catch(Exception e){e.printStackTrace ();} iFIGJS
} *)^6'4=
} c[@_t.%)
K)SWM3r
]4~Yi1]
//打印回应的头信息 pyEQb#
public void logResponseHead(HttpURLConnection con) ~E}kwF
{ |3$Ew.
for(int i=1;;i++) dCx63rF`G
{ S!K<kn`E3
String header=con.getHeaderFieldKey(i); O]:9va
if(header!=null) ~DH9iB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GrF4*I`q
Utility.log(header+" : "+con.getHeaderField(header)); i?L=8+9f
else :>-zT[Lcn
break; hB[bth
} T!/o^0w
} KXKT5E$
_z p<en[
(l5p_x
public void splitterStop() Iv6 lE:)
{ =DwLNyjU4
bStop = true; HDm]njF%qQ
} a\sK{`|X*
]($ \7+
#H$lBCWI
} V#G)w~
s|IBX0^@
Om.%K>V
/* B*/!s7c.
**FileAccess.java b'wy{~l@
*//文件访问(定位，写) x,nl PU
package NetFox; t 7Y*/v&P(
import java.io.*; K6{wM
_'D(>e?
|s3;`Nxu7
public class FileAccessI implements Serializable{ x'EEmjJ
8Z!%rS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hpf0fU
RandomAccessFile oSavedFile; !mv5i%3
long nPos; j$T12
&mX_\w/%
NX\AQVy9
public FileAccessI() throws IOException =A!oLe$%
{ T]wC?gQG
this("",0); cB&_':F
} P!-RZEt$
G=y~)B}
G#[A'tbKk
public FileAccessI(String sName,long nPos) throws IOException Z9:
{ 6UCF w>
oSavedFile = new RandomAccessFile(sName,"rw"); Cab-:2L]
this.nPos = nPos; )4rt-_t<
oSavedFile.seek(nPos); NL]_;\ h
} BP..p ^EPN
"{8j!+]4i
VL)<u"d4
public synchronized int write(byte[] b,int nStart,int nLen) f?d5Ltg
{ $e1.y b%
int n = -1; l%}q&_
try{ .B~}hjOZK
oSavedFile.write(b,nStart,nLen); af<h2r
n = nLen; KBM*7raA
} P;"moluE;
catch(IOException e) WVD48}HF-
{ 3;buC|ky
e.printStackTrace (); YE@yts
} =F|9ac9X
3IRur,|'
"BsK'yo.
return n; .Wt3|?\=nd
} mrr]{K
xc*a(v0
j^=Eu r/
} 7j)ky2r#
$y6 <2w%b
t Cb34Wpf
/* WOZuFS13
**SiteInfoBean.java $B8Vg `+
*/ .K84"Gdx
package NetFox; f I=G>[
qkKl;Z?Y:
uD@ZM
public class SiteInfoBean { |!] "y<
`Pc6 G*p
S3/%;=|
private String sSiteURL; //Site's URL c#TY3Z|
private String sFilePath; //Saved File's Path x</4/d
private String sFileName; //Saved File's Name sJKr%2nVV
private int nSplitter; //Count of Splited Downloading File WP*}X7IS
?fH1?Z\'K
7LU^Xm8
public SiteInfoBean() "LTw;& y
{//nSplitter的缺省值为5 2$Xof
//default value of nSplitter is 5 QL8C!&=
this("","","",5); IDn<5#
} y>}r
|` ~ioF
k Nc-@B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @]q^OMLY
{ F oC $X
sSiteURL= sURL; C*ep8{B
sFilePath = sPath; e4Nd
sFileName = sName; i#>t<g`l
this.nSplitter = nSpiltter; 9V1d`]tP
lS9S7`
j7ZxA*
} OW#0$%f
(Ff}Y.4
N#Rb8&G)b
public String getSSiteURL() Xgd-^
{ w[d8#U
return sSiteURL; Wz.iDRFl
} C<C$df
0F-{YQr>
Ic4#Tk20i
public void setSSiteURL(String value) *VhEl7
{ ?'0!>EjY"
sSiteURL = value; 'UhHcMh:
} IrQ.[?C
J@:Q(
>I\B_q
public String getSFilePath() VA[EY`8
{ *JDz0M4f
return sFilePath; ]UUa/ep-
} rs?Dn6:;B
j yD3Sa3
NH|I>vyN
public void setSFilePath(String value) g_cED15
{ `{:Nt#7
sFilePath = value; _Z]l=5d
} "jyo'r
={;pg(
y#B=9Ri=z
public String getSFileName() A9b(P[!]T:
{ 9oJM?&i
return sFileName; 8^}/T#l
} $h pUI
*@''OyL
\ji\r]k
public void setSFileName(String value) xg/(
{ N_NN0
sFileName = value; \85%d0@3
} Q&:)D7m\)S
]0*aE
?pZU'5le`
public int getNSplitter() 7he,(V
{ B`e/ /
return nSplitter; x9>$197
} L" ejA
fE~KWLm
ISC>]`
public void setNSplitter(int nCount) 6:G&x<{
{ mv99SOe[Fz
nSplitter = nCount; 9JP:wE~y
} F%-@_IsG#
} b5)^g+8)w
8%CznAO"?W
[T_[QU:A
/* .)[E`a
**Utility.java a%Q`R;W
*/ Pg T3E
package NetFox; b\ED<'
,nYa+e
DQY1oM)D!
public class Utility { %U{sn\V
C`[2B0
zNX=V!$
public Utility() ^5]9B<i[Y
{ 5%2~/ "
s U`#hL6;
5V/&4$.U!
} [8za=B/
1R8tR#l
//线程睡眠 &6CDIxH{
public static void sleep(int nSecond) NOs00H
{ e">&B]#}
try{ {2q"9Ox"
Thread.sleep(nSecond); /E<Q_/'Z
} ,]0BmlD
catch(Exception e) zqj|$YNC
{ RjVUm+<
e.printStackTrace (); NE#`ZUr3
} h<?Px"& J
} n>u_>2Ikkj
SYi!%
//日志 T4:H:
public static void log(String sMsg) (enr{1
{ OiAuL:D
System.err.println(sMsg); _"p(/H
} vGsAM*vw6
&,{>b[
3_wR2AU~
public static void log(int sMsg) .^A4w;jPU
{ D6lzcf
System.err.println(sMsg); p,z>:3M
} R(0[bMr3Q
} pSQX
w|G7h=
uM'n4oH
/* =,it`8;
**TestMethod.java XS2/U<sd
*/ G_UxR9Qo
package NetFox; (VzabO
w-.=u3
r% ]^(
public class TestMethod { }vLK-Vv
H6PS7g"
Pq:GvM`
public TestMethod() - &/n[EE
{ ///xx/weblogic60b2_win.exe 0au\X$)Q
try{ `d[ja,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _U`_;=(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3Vj,O?(Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); h (`Erb
fileFetch.start(); {|~22UkF[V
} ^"!j m
catch(Exception e){e.printStackTrace ();} H,!3s<1
]7`)|PJ
pkR+H|
} .v3~2r*&
P`K?k<
`/mcjKQ&9y
public static void main(String[] args) Iw0Q1bK(
{ G=lket6
new TestMethod(); i$A0_ZJKjZ
} ? }2]G'7?
} \*V`w@
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