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)); Tvf%'%h1
} W9>q1
for(int i=0;i<nEndPos.length-1;i++) L h"K"Uv
{ D9`J||]E
nEndPos = nStartPos[i+1]; OL|_@Fv`A
} B ^>}M
nEndPos[nEndPos.length-1] = nFileLength; '?Fw]z1$
} K4938 v
} 8$</HNu,
Z%_"-ENT
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//启动子线程 n<47#-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K cI'P(
for(int i=0;i<nStartPos.length;i++) Eshc"U
{ 1I< <`7'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3_k.`s_Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2L}F=$zz
nStartPos,nEndPos,i); a?#v,4t^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !qe,&JL
fileSplitterFetch.start(); !.>TF+]
} Q _Yl:c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LPr34BK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R$qp3I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D90m..\w
nEndPos = " + nFileLength); =ZdP0l+V=k
// fileSplitterFetch[nPos.length-1].start(); 7!.#:+rg5#
QR4!r@*=
LliOhr4
//等待子线程结束 &K Ti[
//int count = 0; *h59Vaoc
//是否结束while循环 {=n-S2%
boolean breakWhile = false; O3,IR1
:= OdjfhY
k@QU<cvI
while(!bStop) V2-fJ!
{ Hrb67a%b
write_nPos(); LRNgpjE}
Utility.sleep(500); 7P!<c/ E
breakWhile = true; {OHaI ;
M1(+_W`
{s^vAD<~x3
for(int i=0;i<nStartPos.length;i++) s~OGlPK
{ uA]Z"
if(!fileSplitterFetch.bDownOver) MVe:[=VOT|
{ 1&\ A#
breakWhile = false; Fy(-.S1
break; Y![m'q}K
} d8l T+MS=
} r)S tp`p
if(breakWhile) #NU;$&
break; @wa2Z
9C;Hm>WEpP
,khB*h14;h
//count++; t+C9QXY
//if(count>4) bvVEV
// siteStop(); dg#w/}}m
} l)@Zuh
lP$bxUNt
Q4;eN w
System.err.println("文件下载结束！"); >^mNIfdE^=
} M[aF3bbN
catch(Exception e){e.printStackTrace ();} 1eiV[z$?
} 3{wr*L1%-~
3Yu1ZuIR
A6D.bJ)
//获得文件长度 _^{!`*S
public long getFileSize() L< 3U)Gp
{ 4x8e~/
int nFileLength = -1; 7S"W7O1>
try{ {J_1.uN=
URL url = new URL(siteInfoBean.getSSiteURL()); !YJfP@"e6r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =*K~U# uoC
httpConnection.setRequestProperty("User-Agent","NetFox"); |^z?(?w
VXr'Z
(N63k1M
int responseCode=httpConnection.getResponseCode(); []opPQ 1
if(responseCode>=400) Vaj4p""\F
{ a~#MMl
processErrorCode(responseCode); P<&-8QA
return -2; //-2 represent access is error i7@qfe$fR
} ]xJ5}/
hEG-,
~hYTs
String sHeader; 8^/V2;~^,>
mc{gcZIm
879x(JII
for(int i=1;;i++) O0|**Km\+
{ :Bk!YK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v.eNWp
//Utility.log(in.readLine()); )C \ %R
sHeader=httpConnection.getHeaderFieldKey(i); l5?fF6#j
if(sHeader!=null) ;=.i+
{ r3~~4Q4XI>
if(sHeader.equals("Content-Length")) #9HQW:On
{ vn5X]U"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HTfHAc?W
break; Z^P]-CB|6A
} [=Qv?am
} ']'H8Y-M
else }o>6 y>=
break; F_KPhe$
} kzZdYiC
} 3Zy$NsY3
catch(IOException e){e.printStackTrace ();} m53XN
catch(Exception e){e.printStackTrace ();} .uu[f2.N+
+f#oij
,mpvGvAI
Utility.log(nFileLength); >MXE)=
<p_r{
Qi&!Ub]
return nFileLength; z^tws*u],5
} *hJ&7w ~
l`#XB:#U
Kk?]z7s-4
//保存下载信息（文件指针位置） l)JNNcej
private void write_nPos() xR9<I:^&
{ NF/@'QRT
try{ ^F5Q(A
output = new DataOutputStream(new FileOutputStream(tmpFile)); nveHLHvC7
output.writeInt(nStartPos.length); .=y-T=}
for(int i=0;i<nStartPos.length;i++) e1*<9&S
{ L;wfTZa
// output.writeLong(nPos); SZGeF;N
output.writeLong(fileSplitterFetch.nStartPos); D{b*,F:&@)
output.writeLong(fileSplitterFetch.nEndPos); N$Pi4
} 1J(` kQ)c
output.close(); MS`wd
} #bFJ6;g=V
catch(IOException e){e.printStackTrace ();} Gz>M Y4+G
catch(Exception e){e.printStackTrace ();} <<xUh|zE
} B/P E{ /
AsBep
942(a
//读取保存的下载信息（文件指针位置） y.KFz9Qv
private void read_nPos() nEtG(^N
{ PS*=MyNa
try{ fn6;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7/p&]0w
int nCount = input.readInt(); T]&% KQ
nStartPos = new long[nCount]; ~;m3i3D
nEndPos = new long[nCount]; fc}G6P;3{
for(int i=0;i<nStartPos.length;i++) HM'P<<
{ 3['aK|qk.
nStartPos = input.readLong(); };rxpw>ms
nEndPos = input.readLong(); +/">]QJ
} %t*_Rtz\o
input.close(); O<A$,<67
} Qktj
catch(IOException e){e.printStackTrace ();} *2K/)(
catch(Exception e){e.printStackTrace ();} }|MPQy
} b4l=Bg"
iX3Y:
0?]Y^:
private void processErrorCode(int nErrorCode) $L~?!u&N
{ J>H$4t#HX
System.err.println("Error Code : " + nErrorCode); {'.[N79xP
} k!{0ku}]
=F!_ivV
x,f=J4yco
//停止文件下载 ^/K]id7 2
public void siteStop() 3^ct;gz
{ %kod31X3<
bStop = true; xJ/<G$LNJ0
for(int i=0;i<nStartPos.length;i++) 6P0\t\D0
fileSplitterFetch.splitterStop(); \0K3TMl)J
z>\vYR$
"OIra2O
} ||M;[-JoJ
} }8H_^G8
//负责部分文件的抓取 (\CT "u-
**FileSplitterFetch.java br@GnjG
*/ 9-Y.8:A`
package NetFox; 3M5+!H
`k^d)9
Q]Kc<[E
import java.io.*; DEdJH4
import java.net.*; J}$St|1y
)<fa1Gz#^
[8-. T4
public class FileSplitterFetch extends Thread { |.OXe!uU41
v)^8e0vx
\!+sL JP
String sURL; //File URL Dy_ayxm
long nStartPos; //File Snippet Start Position .3yoDab
long nEndPos; //File Snippet End Position ~1_v;LhH5+
int nThreadID; //Thread's ID 29W~<E8K-
boolean bDownOver = false; //Downing is over t`b!3U>I
boolean bStop = false; //Stop identical .ZV-]jgr
FileAccessI fileAccessI = null; //File Access interface AW;ncx;
'U9l
=jz*|e|V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yy,i,c`r
{ PRR]DEz
this.sURL = sURL; |OgtAI9
this.nStartPos = nStart; >I9w|zFA
this.nEndPos = nEnd; *%[L @WF
nThreadID = id; 2X:OS/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -y@# ^SrJ
} 4pYscB
nUp, %z[
~\UH`_83[
public void run() RDX$Wy$@L
{ E%B:6
while(nStartPos < nEndPos && !bStop) B+8lp4V9%
{ 1E1oy(\V
w1#1s|
[iT*L)R4
try{ il=:T\'U9
URL url = new URL(sURL); E46+B2_~zk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XL10W ^
httpConnection.setRequestProperty("User-Agent","NetFox"); !foiGZ3g
String sProperty = "bytes="+nStartPos+"-"; DlD;rL=
httpConnection.setRequestProperty("RANGE",sProperty); !CnkG<5z>
Utility.log(sProperty); 1FkS$ j8:
e-4 Qw#cw
&bIE"ZBjt
InputStream input = httpConnection.getInputStream(); LqDj4[}
//logResponseHead(httpConnection); W7\s=t\
ji8)/
~8A !..Z
byte[] b = new byte[1024]; ^ UB*Q
int nRead; ZxDh94w/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (IE\}QcK
{ I%8>nMTJ
nStartPos += fileAccessI.write(b,0,nRead); ><l|&&e-
//if(nThreadID == 1) ;J]Lzh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Eku+&f@RB
} Vo G`@^s
8p91ni'
bL6, fUS
Utility.log("Thread " + nThreadID + " is over!"); <Qx]"ZP%
bDownOver = true; Hzn6H4Rc
//nPos = fileAccessI.write (b,0,nRead); R6xJw2;_
} i]8+JG6
catch(Exception e){e.printStackTrace ();} y3^>a5z!x
} ,MmX(O0
} D|8Pe{`
<i!:{'%
MBjo9P(
//打印回应的头信息 T@{}!
public void logResponseHead(HttpURLConnection con) y)Y0SY1\j
{ 'yIz<o
for(int i=1;;i++) 8<2 [ F
{ B%L dH
String header=con.getHeaderFieldKey(i); Ub"6OT1tl
if(header!=null) UP+4xG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4^OPzg6Z%p
Utility.log(header+" : "+con.getHeaderField(header)); bvR0?xnq
else !_a@autj
break; RTXl3 jq
} /:BM]K
} q]^Q?r<g::
V\2&?#GZ
qsUob
public void splitterStop() 40M/Gu:
{ $-J=UT2m
bStop = true; x2_?B[z
} '1f:8
~T'!.^/
S.E'fc1
} l ;fO]{
,cF $_7M
JvI6+[
/* 'Cq)/}0
**FileAccess.java x&['g*[L0
*//文件访问(定位，写) 01brl^5K
package NetFox; B]_NI=d
import java.io.*; Gc1!')g!
sX,."@[
DV6B_A{kI
public class FileAccessI implements Serializable{ kJfMTfl,
v ?OIK=Xm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p10i_<J]=
RandomAccessFile oSavedFile; ]Av)N6$&-Z
long nPos; C8oAl3d+h
5(qc_~p^
B=,j$uH
public FileAccessI() throws IOException .!><qVg
{ IT5a/;J
this("",0); =D}]|ie
} /W @k:
o4l=oY:'
|PY*"Ul
public FileAccessI(String sName,long nPos) throws IOException V']{n7a-
{ J Gpy$T{t
oSavedFile = new RandomAccessFile(sName,"rw"); Eg/=VBtc
this.nPos = nPos; '(.vB~m7*+
oSavedFile.seek(nPos); `;\<Fr
} dJYW8pcKT
{] Zet}2
% a9C]?
public synchronized int write(byte[] b,int nStart,int nLen) ymr#OP$<S
{ Xb'UsQ
int n = -1; d8V)eZYXy~
try{ uY"Bgz:=d
oSavedFile.write(b,nStart,nLen); aEJds}eE6)
n = nLen; nUy2)CL[L
} 0+P[0
catch(IOException e) !IUH 5
{ >AUj4d
e.printStackTrace (); s${|A=
} Scfk]DT
6Y 4I $[
rT}k[
return n; @x4IxGlUs
} D?Y j5eOa
A]WR-0Z7
;H%T5$:trP
} _(&XqEX
\'}? j-8
{Bd 0
/* 0DIXd*oj&
**SiteInfoBean.java B?|url6h
*/ .on}F>3k$
package NetFox; {rE]y C^
+ NpHk
Oj`I=O6
public class SiteInfoBean { CdFr YL+F
g~Hmka_fD1
sfuA {c'v
private String sSiteURL; //Site's URL ]>%M%B
private String sFilePath; //Saved File's Path XSDudL
private String sFileName; //Saved File's Name x8v2mnk
private int nSplitter; //Count of Splited Downloading File Qjl.O HO
]DV=/RpJ9B
+:#x!i;W8[
public SiteInfoBean() aIsT"6A~{
{//nSplitter的缺省值为5 D)my@W0,
//default value of nSplitter is 5 QaAWO
this("","","",5); }0(.HMiGj
} Co%EJb"tk
8G6[\P3fQ
2TxHY|4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dEuts*@Q
{ #y4+O;{
sSiteURL= sURL; Ki_8g
sFilePath = sPath; cf7UV6D g
sFileName = sName; hCX_^%
this.nSplitter = nSpiltter; <`/22S"
'A}@XGE:p
Sph:OX8
} Vr1yj
zG0191f
q8_8rp-@
public String getSSiteURL() <JyF5
{ d4]9oi{}
return sSiteURL; kTQvMa-X9D
} OU /=wpt
k:JlC(^h
cIJqF.k
public void setSSiteURL(String value) 9R6]OL)p
{ y~ZYI]` J
sSiteURL = value; "N\tR[P!
} o(5eb;"yi>
%l.5c Sn@
JPq2C\Ka
public String getSFilePath() FO/[7ZH
{ q(C<w
return sFilePath; {*jo,<4ee
} o8A1cb4<T
D+u#!t[q
X\yy\`o
public void setSFilePath(String value) zZ11J0UI
{ ^zs]cFN#%
sFilePath = value; u}:p@j}Zv
} %0<-5&GE
"dN4EA&QJ
ys#V_ysb
public String getSFileName() R3`h$`G
{ *=p[;V
return sFileName; (X?'}Ur
} )A6 eD
|8:IH@K*
@VVDN
public void setSFileName(String value) QwaAGUA
{ ;vDjd2@
sFileName = value; %JsCw8C6?
} MS~|F^g
%9qG|A,cA
F6$QEiDu@
public int getNSplitter() d>f.p"B.gj
{ 0kp#+&)+
return nSplitter; Q-qM"8I
} P t)Ni
8>KBh)q
"yo~;[
public void setNSplitter(int nCount) (r]3tGp
{ 13X\PO'9
nSplitter = nCount; d;-/F b{4
} 7 z#Xf
} ofu {g
n:#gKR-J
`]0E)
/* ox2?d<dC6
**Utility.java (i"@{[IP
*/ WN+D}z]
package NetFox; c@]_V
sr*3uI-)L
m/`"~@}&
public class Utility { Y9K$6lz
-S7y1 )7
-q}c;0vL-a
public Utility() 9PM\D@A{
{ :*`5|'G}
}z$_=v
[It E+{U
} 1syI%I1
:k"VR,riF
//线程睡眠 3ZF-n`
public static void sleep(int nSecond) =WYI|3~Cz
{ *u|bmt
try{ ?<l,a!V'6
Thread.sleep(nSecond); z'(][SB
} J!5>8I(_wX
catch(Exception e) 8)1k>=
{ ^Iz(V2
e.printStackTrace (); V\ 7O)g
} C]xKdPQj%
} Y@+e)p{
YXdd=F
//日志 w[A$bqz
public static void log(String sMsg) `h:$3a:5
{ J'%
System.err.println(sMsg); <DM /"^*
} OjUZ-_J
&f:"p*=a\
ir-= @@
public static void log(int sMsg) Rqk;!N
{ SS/9fT"[
System.err.println(sMsg); )Hp{8c
} 6^Q Bol
} _"Bh 3 7
TCC([
I`~ofq?r
/* rTgCmr'&
**TestMethod.java ^D{!!)O
*/ CfSpwkg
package NetFox; )sh+cfTCb
JIGoF
~Lyy7B9
public class TestMethod { \R6D'Yt
8w:A""
4^KeA".
public TestMethod() K_fQFuj+
{ ///xx/weblogic60b2_win.exe #K5)Rb-H
try{ i"#36CVT~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?3x7_=4t@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "-pQL )f
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4t%g:9]vr
fileFetch.start(); g^V4+3v|a'
} rr@S|k:|
catch(Exception e){e.printStackTrace ();} ~.FZF
zB8 @Wl
h7}D//~p
} aBH!K
&at^~o
}i"\?M
public static void main(String[] args) S#kA$yO
{ '`/Qr~]
new TestMethod(); Vm_waa
} `<0{U]m
} M[C9P.O%w
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