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)); Vwh;QJxb
} bDJ!Fc/
for(int i=0;i<nEndPos.length-1;i++) q1x[hv3 pP
{ V+@}dJS
nEndPos = nStartPos[i+1]; XBkaum4j
} a7F_{Mm
nEndPos[nEndPos.length-1] = nFileLength; kD%MFT4
} y%61xA`#
} bu_@A^ys
d,(q3
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//启动子线程 v{uq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2rf8)8':
for(int i=0;i<nStartPos.length;i++) n8_X<jIp3
{ =N{?ll6x7g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :l!sKT?:d!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /#(IV_Eol
nStartPos,nEndPos,i); k}&wy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a=A12<
fileSplitterFetch.start(); pI8z.JD
} Tj_K5uccU}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UXdc'i g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qj_)^3`e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x>TIx[x
nEndPos = " + nFileLength); }5(_gYr
// fileSplitterFetch[nPos.length-1].start(); Cb? !+U
h9<PP2.(
X1a~l|$h
//等待子线程结束 CrL9|78
//int count = 0; ]BbV\#
//是否结束while循环 `Ds=a`^b
boolean breakWhile = false; mI4GBp
+ZW>JjP*
9< 07# 8c.
while(!bStop) p#]9^oA
{ <3@nv%
write_nPos(); !-470J
Utility.sleep(500); F1-"yX1B
breakWhile = true; 7z1@XO<D
LmqSxHs0Q
'h'pM#D
for(int i=0;i<nStartPos.length;i++) hp(MKfhH
{ -p)`ob-
if(!fileSplitterFetch.bDownOver) .`+~mQ Wn
{ Sq_.RU
breakWhile = false; ciml:"nQ
break; wdBBx\FP
} a]V8F&)g#
} <@ ts[p.
if(breakWhile) /]Y#*r8jRi
break; v@[3R7|4
\9V_[xD+
_[-MyUs
//count++; ),B/NZ/-
//if(count>4) ^[m-PS(
// siteStop(); \M@IKE
} 2SD Z
&R4?]I
Tb?XKO,
System.err.println("文件下载结束！"); _$@fCo0
} ^K1mh9O
catch(Exception e){e.printStackTrace ();} xPUukmG:B
} wk8fa
S>(xx"Ia
FO^6c
//获得文件长度 Oi:Hs
public long getFileSize() 8YRT0/V
{ [j@i^B &
int nFileLength = -1; zzI,iEG
try{ 9M9Fif.
URL url = new URL(siteInfoBean.getSSiteURL()); F#<:ZByjJ@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GiuE\J9i
httpConnection.setRequestProperty("User-Agent","NetFox"); (EWGX |QA
E`^D9:3:)
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int responseCode=httpConnection.getResponseCode(); ZZ^A&%E(a
if(responseCode>=400) `^8mGR>OpI
{ a1I-d=]
processErrorCode(responseCode); ~Uv#)
return -2; //-2 represent access is error y4p"LD5%^
} 44P [P{y
n5A|Zjk;
M=;csazN
String sHeader; G5t7KI
%_Lz0L64k
z$%8'
for(int i=1;;i++) Z.@n7G
{ Y)]VlV!`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C/N;4
//Utility.log(in.readLine()); [O_5`X9|
sHeader=httpConnection.getHeaderFieldKey(i); wAi7jCY%OY
if(sHeader!=null) (&Q!5{$W
{ y,&[OrCm^\
if(sHeader.equals("Content-Length")) &4WA/'>R
{ }15&<s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~$4(|Fq/
break; UYZC% $5x
} UIf#Gy|l
} (NR( )2
else `&fW<5-
break; =d5;F`m
} >T[Y>]
} `fEzE\\!*
catch(IOException e){e.printStackTrace ();} [|*7"Q(
catch(Exception e){e.printStackTrace ();} u?SwGXi~8
8(K:2
tk'&-v'h
Utility.log(nFileLength); xu-bn
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return nFileLength; JiXE{(
} Z D"*fr
o ?05bv
$RI$VyAjD
//保存下载信息（文件指针位置） _ti^i\8~
private void write_nPos() 3A"TpR4f`
{ Kg<~Uf=1
try{ 4j'rbbs/
output = new DataOutputStream(new FileOutputStream(tmpFile)); Er@xrhH
output.writeInt(nStartPos.length); [N4N7yF
for(int i=0;i<nStartPos.length;i++) 8o,0='U
{ h0~<(3zC
// output.writeLong(nPos); 5WfZd
output.writeLong(fileSplitterFetch.nStartPos); CL5^>.}
output.writeLong(fileSplitterFetch.nEndPos); "-Nyf
} p</t##]3ks
output.close(); 8kU(>' ^_:
} l> H'PP~
catch(IOException e){e.printStackTrace ();} i}>EGmv m
catch(Exception e){e.printStackTrace ();} n9&fH
} [=cbzmX[
&*O'qOO<2
GcO:!b*YMp
//读取保存的下载信息（文件指针位置） oM@%2M_O(
private void read_nPos() u"hr4+/
{ RJDk7{(
try{ Txe*$T,(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "X?Zw$gRud
int nCount = input.readInt(); v?3xWXX,
nStartPos = new long[nCount]; o\Fv~^
nEndPos = new long[nCount]; W4nn)qBrh
for(int i=0;i<nStartPos.length;i++) ,s}&|+ '"
{ uInI{>
nStartPos = input.readLong(); M{)eA<6
nEndPos = input.readLong(); A\7sP =
} _f>)G3p
input.close(); .@;5"
} TZ n2,N
catch(IOException e){e.printStackTrace ();} sLTQm*jL
catch(Exception e){e.printStackTrace ();} qycf;Kl:6
} nZNS}|6
tNZZCdB
<Mo{o2F=
private void processErrorCode(int nErrorCode) 8VG~n?y
{ ~LFM,@
System.err.println("Error Code : " + nErrorCode); L*6<h
} ^P [#YO
A`(Cuw-o
O<>+l*bk
//停止文件下载 .pl,ujv
public void siteStop() @*6_Rp"@
{ o^d|/;
bStop = true; {uZ|Oog(p
for(int i=0;i<nStartPos.length;i++) dn=srbJ
fileSplitterFetch.splitterStop(); x=W s)&H_Y
/s(PFN8#Y
Xooh00
} T51oNO%^
} lQ[JA[
//负责部分文件的抓取 M,{;xf
**FileSplitterFetch.java _m a;b<I/<
*/ gLo&~|=L-
package NetFox; >U4bK^/Bp
P$ b5o
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import java.io.*; W S9:*YH
import java.net.*; i8EKzW
w}07u5
Ut1s~b1
public class FileSplitterFetch extends Thread { }p)a7xn}
yVPFH~1@\
WoSKN7*
String sURL; //File URL hD,^mru
long nStartPos; //File Snippet Start Position nddCp~NX
long nEndPos; //File Snippet End Position 0T$`;~
int nThreadID; //Thread's ID \b)P4aL
boolean bDownOver = false; //Downing is over RJT55Rv{
boolean bStop = false; //Stop identical m^/>C-&C
FileAccessI fileAccessI = null; //File Access interface ~xPetkl@
<X1[j9Qtv0
Mj19;nc0I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %>O}bdSf
{ Xpkj44cd@
this.sURL = sURL; >A6PH*x
this.nStartPos = nStart; bgInIe
this.nEndPos = nEnd; Ia^/^>
nThreadID = id; %hBw)3;l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %$_?%X0=t
} vKkvB;F41
$x+ P)5)
&XhxkN$8
public void run() 0q1+5
{ 5rA>2<\pQ
while(nStartPos < nEndPos && !bStop) q7rX4-G$
{ -/7@ A
\IR$~
<`A!9+
try{ zrtbk~v8y
URL url = new URL(sURL); j_zy"8Y{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t3Iij0b~
httpConnection.setRequestProperty("User-Agent","NetFox"); dW^#}kN7V
String sProperty = "bytes="+nStartPos+"-"; ~ :B/`1[m
httpConnection.setRequestProperty("RANGE",sProperty); OXoEA a
Utility.log(sProperty); }4Gn$'e
AZJ|.mV q
^#7&R"
InputStream input = httpConnection.getInputStream(); \/y&l\ k)
//logResponseHead(httpConnection); cf_X=;yaqy
qNkX:|j
Hu!<GB~
byte[] b = new byte[1024]; B=%YD"FAv
int nRead; N,cj[6;T%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MF::At[4
{ .d4&s7n0
nStartPos += fileAccessI.write(b,0,nRead); ]b^bc2:
//if(nThreadID == 1) %NL7XU[~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z`8>$9
} VF"c}
kf)s3I/`(
rN {5^+w
Utility.log("Thread " + nThreadID + " is over!"); `zcpaE.@
bDownOver = true; :\1vy5 _
//nPos = fileAccessI.write (b,0,nRead); 34vH+,!u
} -r{]9v2j
catch(Exception e){e.printStackTrace ();} yv5c0G.D
} 6 )Qe*S
} \'nE{
1a},(ZcdX
OadGwa\:s
//打印回应的头信息 QVR-`d/
public void logResponseHead(HttpURLConnection con) UWBR5
{ ).HnK
for(int i=1;;i++) a'\fS7aE0l
{ "&kXAwe
String header=con.getHeaderFieldKey(i); 072`i46
if(header!=null) JG'&anbm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d8f S79
Utility.log(header+" : "+con.getHeaderField(header)); (Z>vbi%
else !z?:Y#P3
break; Qhn>aeW,
} MXY!N/
} gf|&u4D
3],[6%w
{E>(%vD
public void splitterStop() ;cWFh4_
{ 8DlRD$_:&
bStop = true; of.=n
} \OF"hPq
2wZyUB;
/vFdhh
} `ve5>aw0_Y
4*+)D8
eN I6V/\`
/* uacVF[9|W
**FileAccess.java , @6_sl
*//文件访问(定位，写) !iGZo2LV
package NetFox; 8~h.i1L
import java.io.*; ?u M2|Nk
mv9@Az9
Hh<}~s
public class FileAccessI implements Serializable{ &#[6a&9#[A
+t;j5\HS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +P 9h%/Yk
RandomAccessFile oSavedFile; |Ns[{/
long nPos; Qc"UTvq
9xUAfU
Sc$]ar]S
public FileAccessI() throws IOException >PiEu->P,
{ Tk0Senq,
this("",0); r}])V[V
} X9n},}bJ"
cH\.-5NQ
rc]`PV
public FileAccessI(String sName,long nPos) throws IOException .^* .-8q
{ OLxiY r
oSavedFile = new RandomAccessFile(sName,"rw"); ^T/d34A;SP
this.nPos = nPos; k:kx=K5=4
oSavedFile.seek(nPos); ^0&
} Ea[K$NC)#
9mH/xP:y
\P0>TWE
public synchronized int write(byte[] b,int nStart,int nLen) #+Cu&l
{ ,Tc598D
int n = -1; XQL]I$?
try{ Q68q76
oSavedFile.write(b,nStart,nLen); !XS ;&s7[*
n = nLen; N;]"_"
} `+Ojh>"*z*
catch(IOException e) 2q.J1:lW
{ &8uq5uKg
e.printStackTrace (); *J] }bX
} %,G0)t
}zu?SZH
h48 jKL(
return n; seEG~/U<
} 3]}wZY0
Kr|9??`0E
re\&'%~K
} Vi1= E])
x*uQBNf=
7LY4q/
/* \"@BZ.y
**SiteInfoBean.java v9s/!<j
*/ 7ClN-/4
package NetFox; n$}Cj}eju
li?RymlF
+\n8##oAI
public class SiteInfoBean { d'Z
8(c,b
Mm+kG'Z!S
private String sSiteURL; //Site's URL 8P=z"y
private String sFilePath; //Saved File's Path N v,Yikf
private String sFileName; //Saved File's Name UFy"hJchO
private int nSplitter; //Count of Splited Downloading File eE/E#W8
}<hyW9
m#a0HH
public SiteInfoBean() z tLP {q#
{//nSplitter的缺省值为5 4=E9$.3a
//default value of nSplitter is 5 kG>d^K
this("","","",5); ^ LTKX`p
} O_jf)N\pi
Lx:O Dd
4 u!)QG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hWujio/h
{ h{&}p-X&[
sSiteURL= sURL; Gn_rf"
sFilePath = sPath; {@c)!%2$
sFileName = sName; xi2!__
this.nSplitter = nSpiltter; P~y%
o%E^41M7E
syYe0~
} +84JvOkWi
Hki
s<t*g]0`/
public String getSSiteURL() P=%'2BQ{{
{ b+.P4+
return sSiteURL; !Z*2X ^
} ~;A36M-[.
<g|\]\C|
kFlq@['U
public void setSSiteURL(String value) [80L|?, *
{ P<@V
sSiteURL = value; 8e9ZgC|
} t_PAXj
"[ 091<
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public String getSFilePath() ;LM,<QJ
{ 7LM?<lp]
return sFilePath; ersddb^J]
} Rs<li\GS
CnT]uU
k%5o5Hx
public void setSFilePath(String value) `czL$tN<P
{ cZ{-h
sFilePath = value; M}]E,[
} H53dy*wb$
4]F:QS% x
#G;0yB:76
public String getSFileName() J1Ay^*qRU
{ ?n 9<PMo
return sFileName; 4PwjG;!K
} $y\\?
1/O7KR`K
tiI:yq0
public void setSFileName(String value) O(~74:#*
{ GS%ACk
sFileName = value; brk>oM;t
} XANPI|
[J'O5"T
FaOfe]F
public int getNSplitter() x4&<Vr
{ =@F1J7
return nSplitter; Lb2bzZbhx
} K/+Y9JP9
,U\F<$O
DM3W99PWA
public void setNSplitter(int nCount) <g SZt\
{ biJ"@dm 4
nSplitter = nCount; 'gDhi!h%
} `@$qy&AJ
} +=v6*%y"V
)*=ds,
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/* vR X_}`m8#
**Utility.java 3]=j!_yJf
*/ \^$g%a
package NetFox; 95 7Cr
8.S&J6
rq;Xcc
public class Utility { &R? \q*
hx4X#_)v
8CR b6
public Utility() T)ZO+}
{ 21b
K+=cNC4B
vhA4ol
} 0}a="`p#<
$IZ02ZM$
//线程睡眠 PyOj{WX>W
public static void sleep(int nSecond) E;Akm':
{ zGfF.q}
try{ z+RA
Thread.sleep(nSecond); R4 8w\?L
} \yIan<q
catch(Exception e) v1s.j2T
{ n]?KDID;
e.printStackTrace (); eI%{/>
} MN wMF
} }YiE}+VW|
bqmb|mD
//日志 8|5ttdZ
public static void log(String sMsg) z}>q/!q
{ ]kXiT Yg
System.err.println(sMsg); k,p:!S(bl
} &!|'EW
P4&3jQ[o
z}'-gv\,
public static void log(int sMsg) .c+NsI9}
{ eXN\w]GE
System.err.println(sMsg); N:"S/G>r ;
} =l7@YCj5c
} kx6AMx!nX
ZCP r`H
:Pa^/i
/* }XJA#@
**TestMethod.java M0+xl+c+
*/ `x{*P.]N!<
package NetFox; |ia#Elavo
]LcCom:]
4=BIYC"Lu
public class TestMethod { q5@N//<DNN
gk&
#qx$ p
public TestMethod() 2P`Z>_
{ ///xx/weblogic60b2_win.exe S.u1[Yz^
try{ Pv- i.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,;&j*qFi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y(a0*fh
SiteFileFetch fileFetch = new SiteFileFetch(bean); >s5i
fileFetch.start(); i?{cB!7
} sbeS9vE
catch(Exception e){e.printStackTrace ();} hH&A1vUv
25NTtj:X
A_:CGtv:
} (hB+DPi
})?t:zX#*
]~YY#I":
public static void main(String[] args) y'$Re
{ Fv| )[>z0
new TestMethod(); S2;u!f
} \ 5&-U@
} ZNHlq5
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