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)); h b8L[ 4
} YPCitGBl
for(int i=0;i<nEndPos.length-1;i++) q)AX*T+
{ 1Lp; LY"_
nEndPos = nStartPos[i+1]; 9^nRwo
} +!$`0v
nEndPos[nEndPos.length-1] = nFileLength; $3%+N|L
} }Fox
} 6}|h
T4[/_;1g
e,W,NnCICj
//启动子线程 n.C5w8f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <z>oY2%
for(int i=0;i<nStartPos.length;i++) ( 5uSqw&U
{ $ \o)-3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tE-g]y3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?zbWz=nq
nStartPos,nEndPos,i); :3b02}b7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ed2A\S6tl
fileSplitterFetch.start(); 5OX[)Li
} |k,-]c;6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4%I[.dBnM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aUA)p}/:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k,f/9e+#
nEndPos = " + nFileLength); kQQDaZ8
// fileSplitterFetch[nPos.length-1].start(); $J&c1
5}Xi`'g,
]0j_yX
//等待子线程结束 1MT,A_L
//int count = 0; j2.7b1s
//是否结束while循环 =2ED w_5E
boolean breakWhile = false; TY'61xWi
$em'H,*b3
WIpV'F|t]`
while(!bStop) ,CuWQ'H
{ .aVtd [
write_nPos(); n=AcN
Utility.sleep(500); Jyr V2Tk^
breakWhile = true; bSz7?NAp
o P;6i
Kr `/sWZ
for(int i=0;i<nStartPos.length;i++) F[`dX
{ =
if(!fileSplitterFetch.bDownOver) K}^#VlY9
{ AQT_s9"0
breakWhile = false; Pz\K3-
break; CjP<'0gT
} !\9^|Ef?
} 22U`1AD3U
if(breakWhile) 4v3gpLH
break; v\@RwtP
eF9GhwE=
,sL%Ykr
//count++; "k{so',7z
//if(count>4) KB(W'M_D\
// siteStop(); |D%mWQng
} wJCw6&D,/
8&| o
+}a(jO
System.err.println("文件下载结束！"); ;FRUB@:
} x&0kIF'lq
catch(Exception e){e.printStackTrace ();} NRx I?v
} FO:L+&hr?>
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El;"7Qn
//获得文件长度 M*kE |q/K
public long getFileSize() $Th)z}A}EA
{ EG\;l9T
int nFileLength = -1; Qz#By V:
try{ kP ,8[r
URL url = new URL(siteInfoBean.getSSiteURL()); Hz2Sx1.i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FiUwy/,ZV
httpConnection.setRequestProperty("User-Agent","NetFox"); *Q/^ib9=
C&MqH.K
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int responseCode=httpConnection.getResponseCode(); z[v4(pO6
if(responseCode>=400) C49\'1\6
{ Ez5t)l-
processErrorCode(responseCode); J&,hC%]
return -2; //-2 represent access is error -P/DmSS8V
} X3kFJ{
'yq?xlIj
%HoD)OJe
String sHeader; jS##zC
UGy3B)
1ruI++P
for(int i=1;;i++) C9sU^]#F
{ -ZZJk-::
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /}8Au$nA
//Utility.log(in.readLine()); ^Z?m)qxvB
sHeader=httpConnection.getHeaderFieldKey(i); jgIG";:Q
if(sHeader!=null) 9$;5J
{ $sda'L5^p
if(sHeader.equals("Content-Length")) ]B=*p0~j^n
{ xw 43P.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `@],J
break; SYA~I-OYc
} hQm=9gS
} 4J_HcatOB
else @Xl(A]w%!
break; XNJZ~Mowb
} z}u`45W+
} vHcl7=)Q
catch(IOException e){e.printStackTrace ();} S*h^7?Bu
catch(Exception e){e.printStackTrace ();} x,25ROaHY
N wk
D5P-$1KPt
Utility.log(nFileLength); O@a OKk
.eD&UQ
~&D =;M/
return nFileLength; B]G2P`sN
} 04Zdg:[3-!
fGlvum
y,x 2f%x
//保存下载信息（文件指针位置） pxTtV g.
private void write_nPos() K $- *
{ #C&';HB;y
try{ l%"DeRp,/
output = new DataOutputStream(new FileOutputStream(tmpFile)); }vZf&ib-
output.writeInt(nStartPos.length); ?DUim1KG
for(int i=0;i<nStartPos.length;i++) <|_>r`@%l
{ )y*&&q
// output.writeLong(nPos); ~Yk^(hl2
output.writeLong(fileSplitterFetch.nStartPos); u'l4=e
output.writeLong(fileSplitterFetch.nEndPos); N)g_LL>^
} zU&Iy_Ke.
output.close(); + m-88
} J\*uW|=F
catch(IOException e){e.printStackTrace ();} PzSLE>Q
catch(Exception e){e.printStackTrace ();} Q/]~`S
} lu"0\}7X
$TXiWW+
/ZV2f3;t
//读取保存的下载信息（文件指针位置） \[3~*eX6
private void read_nPos() 7@<.~*Bl6
{ _{k*JT2
try{ t/Io.d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vK)'3%
int nCount = input.readInt(); '9f0UtT|[
nStartPos = new long[nCount]; n<8WjrK
nEndPos = new long[nCount]; N~$>| gn
for(int i=0;i<nStartPos.length;i++) {UP[iw$~
{ ~@c<5 -`{
nStartPos = input.readLong(); 0QZT<Zs
nEndPos = input.readLong(); rt*x[5<
} aO<7a 6
input.close(); iuY,E
} ,.9lz
catch(IOException e){e.printStackTrace ();} )v;O2z
catch(Exception e){e.printStackTrace ();} S3%2T
} S~aWun
jI\@<6O
k^%=\c
private void processErrorCode(int nErrorCode) 2QaE&8vW
{ /lC# !$9vz
System.err.println("Error Code : " + nErrorCode); h s',f
} sr;&/l#7h
AA=Ob$2$
$XQgat@&]
//停止文件下载 ]4H)GWHKg
public void siteStop() G"FO%3&|
{ c_vGr55
bStop = true; Yt#; +*d5
for(int i=0;i<nStartPos.length;i++) !j'LZ7
fileSplitterFetch.splitterStop(); .S|7$_9;b
P'8RaO&d
j ^j"w(a
} v>`Fo[c
} ]F+|C
//负责部分文件的抓取 j<kW+Iio
**FileSplitterFetch.java Kc\8GkdB
*/ _\\Al v.
package NetFox; Cik1~5iF
ir}z^+
*w@1@6?j
import java.io.*; yx|iZhK0:}
import java.net.*; VrRF2(Kn?
^ l#6Es
o~XK*f=(
public class FileSplitterFetch extends Thread { i+O7,"(@
x$-kw{N
ZJ%NZAxy
String sURL; //File URL PyfWIU7O
long nStartPos; //File Snippet Start Position b_TI_
long nEndPos; //File Snippet End Position =?C <@
int nThreadID; //Thread's ID ~b]enG5xS4
boolean bDownOver = false; //Downing is over |^Y"*Y4*h
boolean bStop = false; //Stop identical %}TJr]'F
FileAccessI fileAccessI = null; //File Access interface x"q]~u<rB
/o4e n
f%EHzm/V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `D%i`"~Lf&
{ *4 LS``
this.sURL = sURL; U3&GRY|##
this.nStartPos = nStart; }iKjef#J
this.nEndPos = nEnd; -& (iU#W
nThreadID = id; LujLC&S
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m OUO)[6y
} 0+iRgnd9?
Zy7kPL;b
mQ`atFz:Z
public void run() )dfhy
{ @H`jDaB9
while(nStartPos < nEndPos && !bStop) %"r9;^bj&<
{ -crMO57/
8gNTW7W/
>;9g`d
try{ _fk}d[q0
URL url = new URL(sURL); @@*x/"GJG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6V$ )ym*F
httpConnection.setRequestProperty("User-Agent","NetFox"); H4`>B>\
String sProperty = "bytes="+nStartPos+"-"; 9 RDs`>v
httpConnection.setRequestProperty("RANGE",sProperty); -KC@M
Utility.log(sProperty); 7NRa&W2
2 )o2d^^
^&&Wv'7XQ
InputStream input = httpConnection.getInputStream(); @>(JC]HtR
//logResponseHead(httpConnection); bxYSZCo*
CP\[9#]:
H^kOwmSzh
byte[] b = new byte[1024]; <b"^\]l
int nRead; })] iN"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <xeB9
{ e~ OrZhJ=_
nStartPos += fileAccessI.write(b,0,nRead); SM)"vr_
//if(nThreadID == 1) Pteti
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1/mBp+D
} HYO/]\al
3M?O(oO
KKk~vwW
Utility.log("Thread " + nThreadID + " is over!"); xkFa
bDownOver = true; j xI;clr
//nPos = fileAccessI.write (b,0,nRead); ">=Ep+ix
} 0#Gm# =F
catch(Exception e){e.printStackTrace ();} QaLaw-lx
} 9LPXhxNwB
} Y.I~.66s
.s4vJKK0
AVLY|79#
//打印回应的头信息 \3ydNgl
public void logResponseHead(HttpURLConnection con) *PlKl_nP6
{ <=_!8A
for(int i=1;;i++) dpE^BWv3
{ [L-wAk:Fb
String header=con.getHeaderFieldKey(i); W2-l_{
if(header!=null) eb}XooX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %cDGs^lgA
Utility.log(header+" : "+con.getHeaderField(header)); (D[~Z!
else ;yqHt!N
break; n}Eu^^d
} E3p$^['vx
} g:~q&b[q6
H/`@6, j
13 L&f\b
public void splitterStop() ye(av&Hn
{ 61QA<Wb
bStop = true; o1\N)%
} oR`rs[Kj
AXxyB"7A}
a5m[ N'kah
} ;Q&9t
~G8l1dD
d^54mfgI
/* UxB3/!<5g3
**FileAccess.java ,_V/W'
*//文件访问(定位，写) I+W,%)vb
package NetFox; 7gOu|t
import java.io.*; !|V_DsP
%j@/Tx/
_d7;Z%
public class FileAccessI implements Serializable{ F@ |(
7Q'u>o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ivcy=W=Jk
RandomAccessFile oSavedFile; O%bltNEx1
long nPos; /Dc54Un
^h=gaNL
+-TEB
public FileAccessI() throws IOException D|$0~1y
{ pHoxw|'Y
this("",0); oPBKPGD
} v5 p`=Z@%
w(S&X"~
~#so4<A`3
public FileAccessI(String sName,long nPos) throws IOException 8kd):gZKZ
{ Jk`l{N
oSavedFile = new RandomAccessFile(sName,"rw"); L{;Q6_m
this.nPos = nPos; bhg6p$411
oSavedFile.seek(nPos); I5[@C<b
} o[JZ>nm
|FaK=e
W:WRG8(F
public synchronized int write(byte[] b,int nStart,int nLen) ow`F 7
{ pE+:tMH;
int n = -1; dpge:Qhr
try{ =D?HL?
oSavedFile.write(b,nStart,nLen); i*4v!(E
n = nLen; rK;<-RE<[:
} N5#j}tT
catch(IOException e) T8*;?j*@
{ pFu!$.Fr
e.printStackTrace (); 4u0?[v[Hu
} r-WX("Vvh
#U3q +d+^
N48X[Q*
return n; ^xgPL'
} GqP02P'2
(<Cg|*s
+g1+,?cU
} aAd1[?&
FL$S_JAw
NYxL7:9
/* #IqRu:csp
**SiteInfoBean.java nemC-4}
*/ VggSDb
package NetFox; `4Z:qh+fJ
UpQda`rb
?vik2RW
public class SiteInfoBean { \SgBI/L^
&(o&Y
>G[:Q s
private String sSiteURL; //Site's URL h y\iot
private String sFilePath; //Saved File's Path 3RlNEc%)
private String sFileName; //Saved File's Name @L607[!?
private int nSplitter; //Count of Splited Downloading File )#? K2E
I~ mu'T
]}&HvrOld
public SiteInfoBean() pma=*
{//nSplitter的缺省值为5 AS4oz:B
//default value of nSplitter is 5 80gOh:
this("","","",5); < jX5}@`z
} p~(STHDe#
( YZ2&
-\Z`+kY?p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ][8`}ki 1
{ FId,/la
sSiteURL= sURL; ME5M;bz(
sFilePath = sPath; #z*,-EV|
sFileName = sName; &g8Xjx&zj
this.nSplitter = nSpiltter; ?ZhBS3L
\m<$qp,n
),%@X
} }1a(*s,s-^
EyV5FWb58
(2RuQgO
public String getSSiteURL() zSOZr2- ^a
{ +t]Ge >S
return sSiteURL; :hf%6N='kI
} :$XlYJrjK
!bX
3r?T|>|
public void setSSiteURL(String value) 4~vn%O6n
{ O^3XhTW^\~
sSiteURL = value; 95/;II
} ZxCXru1
"SC]G22
I;{Ua*
public String getSFilePath() >@Na6BH5v
{ aCfWbJ@qiG
return sFilePath; A(+V{1L'
} +5:9?&lH
4~d:@Gmk&
=,s5>2
public void setSFilePath(String value) =6qSo @
{ btDTC9O
sFilePath = value; 7G Jhc
} Z|3[Y@c\
Iqj?wI1)
OskQ[ e0
public String getSFileName() JUq7R%"h6
{ j}G9+GX~,
return sFileName; =<P$mFP2*
} h~=~csya:
\rH0=~F-P
@~i :8
public void setSFileName(String value) WjvgDNk
{ hu~XFRw15
sFileName = value; (J j'kW6G6
} 1<0Z@D~F
Q6r
FJsM3|{2=d
public int getNSplitter() }e>OmfxDBt
{ t+Qx-sW
return nSplitter; PD^Cj?wm
} fDChq[LAn
Ece=loV*l
Ol8Yf.e_
public void setNSplitter(int nCount) iu`B8yI
{ @3?dI@i(
nSplitter = nCount; 85:mh\@-G
} 5RKs2eV
} u)Vn7zh
fQf5%
L,sXJ23.
/* 8?hj}}H
**Utility.java u X(#+
*/ KP gzB^>
package NetFox; 4B-+DH>{6
wf~n>e^e
1@q"rPE^
public class Utility { Tqx
PWS5s^WM
KN.WTaO
public Utility() |_16IEJ
{ or[!C%
9lqD~H.
6KX/Yj~B
} [h0)V(1KR
t#nRa Pzp
//线程睡眠 \*30E<;C_
public static void sleep(int nSecond) }t1J`+x%
{ ,'@t.XP
try{ 4z^VwKH\j
Thread.sleep(nSecond); B1J2m^
} 5Qxm\?0J
catch(Exception e) {fn1sGA
{ G=m18Bv{
e.printStackTrace (); E~`<n]{G-C
} F2',3
} vgKdhN2kI
@zig{b8
//日志 x#'v}(v
public static void log(String sMsg) R7Z!
{ <a&$D
System.err.println(sMsg); +wm%`N;v<
} B\quXE)
Y".4."NX
mz3Dt>
public static void log(int sMsg) 8LGNV&Edg
{ :Gf
System.err.println(sMsg); ~L9I@(/S
} G]gc*\4
} +\25ynM
#9q ]jjH E
evz@c)8
/* '-rRD\"q
**TestMethod.java Z':w X
*/ Jmun^Q/h
package NetFox; J|DY /v
LDj*~\vsq
XM:\N$tg
public class TestMethod { fD2)/5j1
RFLw)IWkL_
/(DnMHn\
public TestMethod() yjIA`5^
{ ///xx/weblogic60b2_win.exe M)sAMfuUw
try{ o|y1m7X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J{PNB{v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pr#uV3\
SiteFileFetch fileFetch = new SiteFileFetch(bean); HEe_K!_
fileFetch.start(); x]~&4fp
} <4.j]BE
catch(Exception e){e.printStackTrace ();} T}Ve:S
G)&S%R!i\N
I"HA( +G
} `"y:/F"{
N)
:rEZR`
public static void main(String[] args) |eP5iy wg
{ #bGYd}BfD
new TestMethod(); b$>1_wTL
} F+<Z%KuCu
} FA}y"I'W
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