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)); <d<RK@2-
} }-@I#9
for(int i=0;i<nEndPos.length-1;i++) - coy@S=.'
{ :dbV2'vIQ
nEndPos = nStartPos[i+1]; `QAh5r"
} D1~^\)*
nEndPos[nEndPos.length-1] = nFileLength; )ldUayJ
} {G]`1Q1DR
} 'v`~(9'Rcj
l2M/,@G
kBUufV~
//启动子线程 S&`O\!NF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9/QS0
for(int i=0;i<nStartPos.length;i++) <e^6.!;W
{ :EaiM J_=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X!?wL0n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =1&}t%<X
nStartPos,nEndPos,i); :'b%5/ ^q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m>+A*M8
fileSplitterFetch.start(); i!ds{`d
} v,@E}F~-f1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3# :EK M~!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zZw@c?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Hm<M@M$aG
nEndPos = " + nFileLength); xP{m9_Qj
// fileSplitterFetch[nPos.length-1].start(); PH{c,
[j1^$n 8V
's/27=o
//等待子线程结束 olslzXn7o
//int count = 0; aq$62>[
//是否结束while循环 6#/LyzZq|
boolean breakWhile = false; .M`LUb"!
)SC`6(GW
q8tP29
while(!bStop) "&s9cO.H
{ Ed8U;U b
write_nPos(); W=!F8g|Qz
Utility.sleep(500); sL;z"N@PK
breakWhile = true; eF*TLI<[^I
KX$qM g1j
aslNlH6
for(int i=0;i<nStartPos.length;i++) y`T--v3mI
{ 6Eij>{v
if(!fileSplitterFetch.bDownOver) .)?2)Fl
{ H{&a)!Ms
breakWhile = false; ;N9n'Sq4
break; lsN/$M|}
} @)S sKk|
} Cw@k.{*7,
if(breakWhile) hG< a
break; `mh-pBVD1
?T$*5d
~k"eEV p
//count++; wGZ>iLe:
//if(count>4) :4Id7Ce
// siteStop(); ?nj"Ptzs
} Mt]=v}z
M^!C?(Hx^x
A?^A*e
System.err.println("文件下载结束！"); u)N2
} ski1f
catch(Exception e){e.printStackTrace ();} /7!_un9
} g!~-^_F
58a)&s[+
KY;uO 8Te
//获得文件长度 Po2_ 0uX
public long getFileSize() Ncs4<"{$
{ '2Mjz6mBDA
int nFileLength = -1; {PP^Rb)
try{ tIc0S!H#
URL url = new URL(siteInfoBean.getSSiteURL()); 7TMDZ*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P':]A{<Z
httpConnection.setRequestProperty("User-Agent","NetFox"); %Q>~7P
/ynKKJx<Y
%B*<BgJ;4F
int responseCode=httpConnection.getResponseCode(); EU&6Tg
if(responseCode>=400) @U7#, G
{ (mOqv9pn
processErrorCode(responseCode); rH [+/&w5
return -2; //-2 represent access is error T<9dW?'|
} u(TgWp5WF
ly[\mGr
mfp`Iy"}+
String sHeader; P|!/mu]
75^)Ni
F|h,a;2
for(int i=1;;i++) 3.GdKP.%
{ @[[Cs*-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ouu-wQ|(mM
//Utility.log(in.readLine()); cN[q)ts
sHeader=httpConnection.getHeaderFieldKey(i); 6cgpg+-a
if(sHeader!=null) jN5} 2 p*
{ f0HV*%8
if(sHeader.equals("Content-Length")) ^bY^x+d
{ inq4CGY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hhh: rmEZl
break; \M3NasZ
} )U/@J+{{
} -?2&5YB
else US*<I2ZLh
break; f6aT[Nw<
} 1z$}*`
} EFT02#F_f
catch(IOException e){e.printStackTrace ();} jmZ|b6
catch(Exception e){e.printStackTrace ();} #4|i@0n}D
O. .@<.
,&pF:qlF
Utility.log(nFileLength); 3gfV0C\
1_dMe%53
h#6 jUQ
return nFileLength; HnKF#<
} V+"*A
t"Vr;0!{
uq#h\p|
//保存下载信息（文件指针位置） \Im\*A
private void write_nPos() ^w.(*;/
{ k0Vo
try{ 59%f|.Z)
output = new DataOutputStream(new FileOutputStream(tmpFile)); zdpLAr
output.writeInt(nStartPos.length); T\b";+!W
for(int i=0;i<nStartPos.length;i++) 4-?`#
{ JNA}EY^2I.
// output.writeLong(nPos); J1v0 \
output.writeLong(fileSplitterFetch.nStartPos); $/U^/2)
output.writeLong(fileSplitterFetch.nEndPos); RWm Q]
} `sp'Cl!
output.close(); tRrY)eElS
} jP7+s.j>
catch(IOException e){e.printStackTrace ();} Hh'14n&W
catch(Exception e){e.printStackTrace ();} $d"f/bRWy
} 4`'BaUU(
xYkgNXGs5
owS@dbO
//读取保存的下载信息（文件指针位置） ^zluO
private void read_nPos() Q!A3hr$IF
{ x2IU PM
try{ fylA0{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JV6U0$g_S
int nCount = input.readInt(); CR|&VxA
nStartPos = new long[nCount]; -L'`d
nEndPos = new long[nCount]; )GT?Wd
for(int i=0;i<nStartPos.length;i++) a.*j8T
{ hZ/
nStartPos = input.readLong(); <cS7L0h
nEndPos = input.readLong(); !Pjg&19
} Hn]n]wsLy
input.close(); 2BU)qv-
} 1NHoIX
catch(IOException e){e.printStackTrace ();} aD3F!Sn
catch(Exception e){e.printStackTrace ();} F3r
} D"XQ!1B%
nm|m1Z+U
`m0Uj9)#
private void processErrorCode(int nErrorCode) bqwW9D(
{ u|*|RuY
System.err.println("Error Code : " + nErrorCode); ydFhw}1>
} dcTM02kEh
[^BUhm3a
Z.OrHg1
//停止文件下载 U:p"IY#%
public void siteStop() yt#;3
{ xgw)`>p,W
bStop = true; 5z mHb
for(int i=0;i<nStartPos.length;i++) ?g#t3j>zoF
fileSplitterFetch.splitterStop(); j I@$h_n
8!`.%)- 4
t }C ^E
} F?AfB[PM
} yl+)I
//负责部分文件的抓取 ITY!=>S-
**FileSplitterFetch.java 4bjp*1*]
*/ J9t?]9.,:
package NetFox; yacGJz^f=
IMw)X0z
#$rT 4Nc;
import java.io.*; i1\ /\^
import java.net.*; f<:SdtG5
)$N{(Cke2T
V>j`
public class FileSplitterFetch extends Thread { s31_3?Vdf,
hg/&[/eodm
n\al}KG
String sURL; //File URL ]p.f*]
long nStartPos; //File Snippet Start Position RKb3=} *C
long nEndPos; //File Snippet End Position y:zT1I@>
int nThreadID; //Thread's ID 4$w-A-\t
boolean bDownOver = false; //Downing is over BQ)43Rr>
boolean bStop = false; //Stop identical w/Dm
FileAccessI fileAccessI = null; //File Access interface w3UJw
84\o7@$#
6]49kHgMhe
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fB}5,22
{ =zGz|YI*?
this.sURL = sURL; uKzz/Y{
this.nStartPos = nStart; Z"KuS
this.nEndPos = nEnd; *fX)=?h56
nThreadID = id; +ANIm^@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zpd>' ${4
} A0sW 9P6F
V]cY+4Y
`g1~ya(MC
public void run() ")buDU6_
{ u`nn{C4D"
while(nStartPos < nEndPos && !bStop) 'J2P3t
{ -^"?a]B
lY?d*qED
5-po>1g'
try{ FeRuZww._J
URL url = new URL(sURL); G\AQql(f4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ->{WO+6(
httpConnection.setRequestProperty("User-Agent","NetFox"); CU&,Kq@
String sProperty = "bytes="+nStartPos+"-"; x"T^>Q
httpConnection.setRequestProperty("RANGE",sProperty); O:R{4Q*5
Utility.log(sProperty); Ik)Q0_<a
py4_hj\v
|{"7/~*[
InputStream input = httpConnection.getInputStream(); WR1,J0UU6
//logResponseHead(httpConnection); }PuO$ L
#<3\}*/
s``L?9
byte[] b = new byte[1024]; IGQ8-#=
int nRead; EHjhez
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @>ZjeDG>
{ g"f^YEQ_
nStartPos += fileAccessI.write(b,0,nRead); ,"ZlY}!Gn
//if(nThreadID == 1) ajr8tp'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x{5*%}lX8
} ^Y |s^N
Rw%KEUDm
r2w7lf66!
Utility.log("Thread " + nThreadID + " is over!"); nVD YAg'
bDownOver = true; I78pul8!
//nPos = fileAccessI.write (b,0,nRead); t]XJq
} ocUu
catch(Exception e){e.printStackTrace ();} 1jVcL)szU
} Op~+yMef
} iDJ2dM}v
&rKhB-18)
wl9icrR>
//打印回应的头信息 6 [E"
public void logResponseHead(HttpURLConnection con) O:)@J b2
{ :f:C*mYvu
for(int i=1;;i++) hI0l2OE
{ #u^d3 $Nj
String header=con.getHeaderFieldKey(i); zZ-*/THB@R
if(header!=null) ^lj>v}4fkW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4G ?k31,k
Utility.log(header+" : "+con.getHeaderField(header)); (z{xd
else f0+
break; 9:s!#FYFM
} jL&F7itP
} AaVlNjB
uWE@7e4'I
zT8K})#
public void splitterStop() ML-g"wv
{ hrK^oa_[W
bStop = true; `N+ P,
} v3Kqs:"\
]LjW,b"
*v&RGY[>
} #q%/~-Uk
he@swE&
e6Y0G,K
/* wvD|c%
**FileAccess.java 4j5plm=
*//文件访问(定位，写) w'C(? ?mH
package NetFox; `KN{0<Ne
import java.io.*; LJ?7W,?
dL>ZL1.$
Wp $\>
public class FileAccessI implements Serializable{ %-D2I
&>SE9w/?o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8}2 `^<U
RandomAccessFile oSavedFile; oVdmgmT.Y
long nPos; ZC"p^~U_e[
uP.3(n[&
JXrMtSp\
public FileAccessI() throws IOException WD<M U ]
{ '0+-Hit?
this("",0); zKo,B/Ke4
} q-'zZ#
HzV3O-Qz]
:7gIm|2"]
public FileAccessI(String sName,long nPos) throws IOException gU:jx
{ }QK-@T@4<
oSavedFile = new RandomAccessFile(sName,"rw"); 9#+X?|p+0
this.nPos = nPos; h1xYQF_`Z
oSavedFile.seek(nPos); "bqB@)
} ]'Bz%[C)
umY4tNe]$
+u7mw<A 8
public synchronized int write(byte[] b,int nStart,int nLen) k# /_Zd
{ czafBO6
int n = -1; Lq:Z='Kc
try{ FKPI{l
oSavedFile.write(b,nStart,nLen); (c;$^xZK
n = nLen; HQ"D>hsuU
} :EZTJu
catch(IOException e) 'j|;M
{ AyddkjX
e.printStackTrace (); 9!tRM-
} vq|W&
Tw$lakw
\%UA6uj
return n; 9i n&\
} 8@ b83
a4?:suX$
UPH:$Fk&
} *g7dB2{
HA| YLj?|g
uCx\Bt"VI
/* dLLF#N
**SiteInfoBean.java -YD6
*/ )]'?yS"
package NetFox; p tMysYT'
WL<Cj_N_{H
{A{=RPL
public class SiteInfoBean { J?HYN%
Eg>MG87
F9N)UW:w
private String sSiteURL; //Site's URL YoJN.],gf
private String sFilePath; //Saved File's Path aB.`'d)V
private String sFileName; //Saved File's Name ~b*f2UVs
private int nSplitter; //Count of Splited Downloading File ~u3E+w
g9g^zd,
@wbV@
public SiteInfoBean() u9J;OsnHK
{//nSplitter的缺省值为5 C,.$g>)MZK
//default value of nSplitter is 5 :Fm)<VN"
this("","","",5); p "u5wJ_
} dx?4)lb
i!9yN:m0
L"9,K8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zxY
{ vn7<>k>dx
sSiteURL= sURL; >zVj+
sFilePath = sPath; 4 QD.'+L
sFileName = sName; UT%^!@u
this.nSplitter = nSpiltter; #)z_TM07P
5^+>*z
YQLp#
} 4gzrxV
x xWnB
?"\X46Gz;
public String getSSiteURL() s${ew.eW
{ pbt/i+!
return sSiteURL; 6x7pqHM
} f 0D9Mp
F<VoPqHq
r$<[`L+6
public void setSSiteURL(String value) $ac VJI?
{ eKsc ["
sSiteURL = value; ?VmEbl
} |hk?'WGc`0
g)nsP
i{vM NI{
public String getSFilePath() v!JQ;OX
{ B_$hi=?TTd
return sFilePath; [9Q}e;T
} \4zb9CxOZ
3=SIIMp7=
nO.RB#I$F
public void setSFilePath(String value) gTa6%GM>
{ !Nua
sFilePath = value; {@ ygq-TZ
} p;$Vw6W=
[<CIh46S.
KsZd.Rf=@
public String getSFileName() lC):$W
{ KG=h!]Meq
return sFileName; '[V}]Z>-
} m_ >+$uL
Kw_> X&GcJ
qD0sD2 x
public void setSFileName(String value) WCJ$S\#
{ av~dH=&=
sFileName = value; S&N[@G
} FyY<Vx'yQ
x=]PE}<E
`IN/1=]5
public int getNSplitter() Qv4g#jX{
{ oS.fy31p
return nSplitter; cG{>[Lf
} " b?1Yc-
w&VMb&<
Teo&V
public void setNSplitter(int nCount) `q":i>FP2
{ NWx.l8G
nSplitter = nCount; vOMmsU F
} A|Z'\D0
} ! 3&_#VO
TX/Ng+v S
fZ8at
/* Y367Jr@^N
**Utility.java [(Jj@HlP6T
*/ c:>&iB-Yu
package NetFox; >d1gVBhk
hqr V {c
DSb/+8KT
public class Utility { n\CQ-*;l
[,_4#Zz
--X1oC52A
public Utility() dG{D2~#
{ Dl/Jlsd@
b d!|/Lk
"j(?fVx
} D`|.%
_@-D/g
//线程睡眠 YSQB*FBz
public static void sleep(int nSecond) iobL6SUZ
{ I)9un|+,y
try{ +aa( YGL
Thread.sleep(nSecond); "'M>%m u
} io8c[#"uU
catch(Exception e) 1#o>< ?
{ 1a|Z!Vzi
e.printStackTrace (); XnBpL6"T`
} 1K<4Kz~
} <X5'uve
}1N$4@
//日志 wTT_jyH)
public static void log(String sMsg) HW0EPJ
{ kB`t_`7f
System.err.println(sMsg); ,VtrQb)Yf
} u2p5*gzZ
=v(MdjwFl
!kzC1U
public static void log(int sMsg) &PfCY{_
{ OIT9.c0h
System.err.println(sMsg); $m$tfa-
} oN0p$/La
} fa~u<m
{|{}]B
b7X-mkF
/* M!KHBr
**TestMethod.java y-Xd~<*Ia
*/ *Ey5F/N}$H
package NetFox; hJ)>BeH0
#1>DV@^F
) ?AlQA
public class TestMethod { BseK?`]U"
uydy[n\
vXdz?
public TestMethod() CA0SH{PdW&
{ ///xx/weblogic60b2_win.exe XET'XJWF%
try{ ;B8#Nf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O{0TS^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "K.XoG4|
SiteFileFetch fileFetch = new SiteFileFetch(bean); }Pu|%\
fileFetch.start(); a!`b`r-4
} H|E{n/g
catch(Exception e){e.printStackTrace ();} t>W^^'=E
i\4Qv"%
994
} w&A&BE^O/
!OM P]
Rnl 4
public static void main(String[] args) OokBi 02b
{ h)O<bI8
new TestMethod(); s_`PPl_D$K
} @B<B#
} #g ;][
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