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)); }U(bMo@;
} *b_Iby-ZD
for(int i=0;i<nEndPos.length-1;i++) }4T`)
{ 3B='f"G
nEndPos = nStartPos[i+1]; ))dw[Xa
} 1G6 \}El95
nEndPos[nEndPos.length-1] = nFileLength; C+t0Zen
} O')=]6CQ*
} h;#046-7
psse^rFg
J(K/z,4h
//启动子线程 \*&?o51!e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $) M2
for(int i=0;i<nStartPos.length;i++) ff7#LeB9
{ !Eg2#a?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &8pGq./lr=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !C|Z+w9Y
nStartPos,nEndPos,i); {P,hH~!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~;z] _`_Va
fileSplitterFetch.start(); M~7Cb>%<
} VC0Tqk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "UreV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ke:WlDf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KLW>O_+
nEndPos = " + nFileLength); +_kA&Q(t
// fileSplitterFetch[nPos.length-1].start(); 6"o=`Sq
c&P/v#U_
1V9AnzwX
//等待子线程结束 gKcBx6G Q
//int count = 0; Td|u-9OM
//是否结束while循环 Rc3!u^?u
boolean breakWhile = false; 4x}U+1B
cIQbu#[@
8AuE:=?,,
while(!bStop) MGq\\hLD\-
{ ]R>NmjAI
write_nPos(); _BY+Tfol
Utility.sleep(500); 4Y}Nu
breakWhile = true; z]SEPYq:
*>"NUHq
%6%mf>Guf
for(int i=0;i<nStartPos.length;i++) nW*cqM%+
{ $)$r
if(!fileSplitterFetch.bDownOver) ^pH8'^n
{ /qJCp![X
breakWhile = false; oc]:Ty
break; Mtv{37k~
} H3*]}=
} V?'p E
if(breakWhile) M>|ZBEK
break; 4F9!3[}qF
:4-,Ru1C"
+Adk1N8
//count++; ^>&#F[aT
//if(count>4) @C!&lrf3
// siteStop(); NP\mzlI~@
} @"BhKUoV$K
X(eW+,H
S[2?,C<2=
System.err.println("文件下载结束！"); ~Kt1%&3{a?
} /V{UTMSz
catch(Exception e){e.printStackTrace ();} |pv$],&&:
} gKl9Nkd!R
Sgv_YoD?-
l*OR{!3H$
//获得文件长度 -b{<VrZ
public long getFileSize() cD6^7QF
{ W7'<Jom|?
int nFileLength = -1; ']>9/r#
try{ 8B &EH+
URL url = new URL(siteInfoBean.getSSiteURL()); pDYJLh-C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [U",yN]d
httpConnection.setRequestProperty("User-Agent","NetFox"); 343d`FRa}
DO*
+v 3:\#
int responseCode=httpConnection.getResponseCode(); j'U1lEZm2
if(responseCode>=400) K:jn^JN$
{ i!}6FBZ
processErrorCode(responseCode); Axns
return -2; //-2 represent access is error S<NK!89
} akt7rnt?i
g)^s+Y
EnlAgL']|
String sHeader; :H3/+/x
i0$*):b
Q.$Rhjb
for(int i=1;;i++) jc)7FE
{ Ky"FL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,dTmI{@O
//Utility.log(in.readLine()); V4NQcy? H
sHeader=httpConnection.getHeaderFieldKey(i); 5 ,-8oEUL
if(sHeader!=null) HUD0 @HQI
{ $l"%o9ICG
if(sHeader.equals("Content-Length")) =?0v,;F9|
{ !L9OJ1F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s5{=lP
break; l*z%Jw
} |u?VlRt
} 1s@QsZ3
else 2/r8%Sq
break; zsQ|LwQ
} ("t'XKP&N
} bA,Zfsr6#
catch(IOException e){e.printStackTrace ();} mi<Q3;m
catch(Exception e){e.printStackTrace ();} X*@ tp,t
jzJTV4&zjs
mN}szW,
Utility.log(nFileLength); D0xQXC3$`
c/tB_]
QHZ",1F
return nFileLength; xmcZN3 ){+
} vio>P-2Eho
f\dfKNm6
v.Q#<@B^:
//保存下载信息（文件指针位置） v;e8W9M
private void write_nPos() Jg[Ao#,==
{ =/46;844T
try{ vuPNru" 2
output = new DataOutputStream(new FileOutputStream(tmpFile)); X2Z)> 10
output.writeInt(nStartPos.length); CUI+@|]%
for(int i=0;i<nStartPos.length;i++) NT*r7_e
{ |K Rt$t
// output.writeLong(nPos); T2<%[AF0
output.writeLong(fileSplitterFetch.nStartPos); :gU5CUm
output.writeLong(fileSplitterFetch.nEndPos); 0GrM:Lh y
} YPI)^ }
output.close(); c**&,aL
} y0mNDze
catch(IOException e){e.printStackTrace ();} RSym9t90t
catch(Exception e){e.printStackTrace ();} UTyV6~
} hk4t #Km
8i`>],,ch
( ~5M{Xh
//读取保存的下载信息（文件指针位置） r)'vn[A
private void read_nPos() |} b+$J
{ \6&Ml]1
try{ `9K5 ;]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9m$;C'}Z
int nCount = input.readInt(); <Pt?N2]A|
nStartPos = new long[nCount]; Z)W8Of_
nEndPos = new long[nCount]; )ciP6WzzbI
for(int i=0;i<nStartPos.length;i++) W]ca~%r
{ g) u%?T
nStartPos = input.readLong(); +,>%Yb=EA
nEndPos = input.readLong(); "g^i%
} 7amVnR1f
input.close(); hvw9i7#
} >Dr(%z6CN
catch(IOException e){e.printStackTrace ();} B{j><uxl
catch(Exception e){e.printStackTrace ();} X"r)zCP+t
} EYq?NL='
[UzD3VPg
<@-O06
private void processErrorCode(int nErrorCode) 8O,\8:I#
{ ^)gyKl:E'
System.err.println("Error Code : " + nErrorCode); wL?Up>fr
} :9UgERjra
J/4T=:\
:uo1QavO@,
//停止文件下载 $gBQ5Wd
public void siteStop() ZiJF.(JS
{ C!5A,|DX
bStop = true; 8~o']B;lJ
for(int i=0;i<nStartPos.length;i++) 7a'yO+7-)
fileSplitterFetch.splitterStop(); C.92FiC
!lgL=Ys(
#,d~t
} ?N<My&E
} ;9T}h2^`B
//负责部分文件的抓取 F(HfXY3
**FileSplitterFetch.java >s{I@#9
*/ D9oNYF-V
package NetFox; &ry*~"xoh
qLDj\%~(
elCYH9W^
import java.io.*; !'jq.RawP
import java.net.*; k <oB9J
|NfFe*q0;8
^Qs}2%
public class FileSplitterFetch extends Thread { }]vUr}Els
:DN!1~ZtW
-XV,r<''
String sURL; //File URL +'?Qph6o,7
long nStartPos; //File Snippet Start Position {q0+PzgP
long nEndPos; //File Snippet End Position u<BU4c/p
int nThreadID; //Thread's ID -&8( MT*
boolean bDownOver = false; //Downing is over nHm}^.B*+
boolean bStop = false; //Stop identical `$6o*g>:
FileAccessI fileAccessI = null; //File Access interface YJ _eE
C$y6^/7)
YvU%OO-+,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K&|h%4O
{ RehmVkT
this.sURL = sURL; ,&t+D-s<f
this.nStartPos = nStart; !!1?2ine
this.nEndPos = nEnd; V,&%[H [
nThreadID = id; "<ZV'z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9*)&hhBs,
} dEoIVy_9R
\Z]+j@9
X8|H5Y:
public void run() RPz[3y
{ ]nTeTW
while(nStartPos < nEndPos && !bStop) ?.?)5 &4
{ y7,fFUKl
p&<Ssc
~R!1{8HP
try{ buGBqx[
URL url = new URL(sURL); u;`]U$Qq9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OpUfK4U)
httpConnection.setRequestProperty("User-Agent","NetFox"); Dl;hOHvKk
String sProperty = "bytes="+nStartPos+"-"; 7AqgX0)
httpConnection.setRequestProperty("RANGE",sProperty); JmI%7bH@
Utility.log(sProperty); 7Q .Su
\zO.#H
*d1BpR%
InputStream input = httpConnection.getInputStream(); kt6x"'"1
//logResponseHead(httpConnection); _\WR3Q!V
Dh I{&$O/
) O0Cz n
byte[] b = new byte[1024]; 8MJJ w;
int nRead; AjVC{\Ik
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m!V,W*RNr
{ k"N>pjgd$
nStartPos += fileAccessI.write(b,0,nRead); yE$PLM
//if(nThreadID == 1) %6m/ve
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uwNJM
} |#TU"$;
@?,x3\N-
)(}[S:`
Utility.log("Thread " + nThreadID + " is over!"); -H-U8/WC
bDownOver = true; sl'4AK~\
//nPos = fileAccessI.write (b,0,nRead); Ln&pe(c
} ;sB=f
catch(Exception e){e.printStackTrace ();} E'QAsU8pP
} -+".ut:R
} 0]DOiA
8?yIixhw
.hT>a<
//打印回应的头信息 O =Z}DGa+
public void logResponseHead(HttpURLConnection con) .a%6A#<X
{ %F*9D3^h
for(int i=1;;i++) dAI^P/y%
{ e+[*4)Qfy
String header=con.getHeaderFieldKey(i); 3<xE_ \DR
if(header!=null) BhJ>G%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VE|:k:};
Utility.log(header+" : "+con.getHeaderField(header)); p_gN}v
else _jQ:9,; A
break; bfxE}>
} "Lp.*o
} ng1E'c]0@
k<9,Ypa
"-4|HA
public void splitterStop() _H+]G"k/r
{ H,7='n7"
bStop = true; "#d$$ 8
} 3lUVDNbZ
&[ })FI
D;,p?]mgO~
} `Skvqo(5:
)PYPlSQ*V
e={O&9Z
/* aHhLz>H'
**FileAccess.java ?8>a;0
*//文件访问(定位，写) =E-x0sr?
package NetFox; XcJ5KTn
import java.io.*; pS?D~0Nb
(XZ[-M7
v{"nyW6#
public class FileAccessI implements Serializable{ SoIK<*J
&CG94
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R?wZ\y Ks}
RandomAccessFile oSavedFile; @2Z|\ojJ
long nPos; t^#1=nK
f|> rp[Gk
YU,zQ V'
public FileAccessI() throws IOException yFE0a"0y
{ N8sT?
this("",0); [L%Ltmx
} xQ9t1b|{e
Tuvs}
*DJsY/9d}'
public FileAccessI(String sName,long nPos) throws IOException WIWo4[(
{ b_+o1Zy`
oSavedFile = new RandomAccessFile(sName,"rw"); 0|GYtnd
this.nPos = nPos; Es=G' au
oSavedFile.seek(nPos); [@K'}\U^+
} H1N@E}>|
(kL"*y/"p
P]+B}))
public synchronized int write(byte[] b,int nStart,int nLen) X@~/.H5
{ pSx5ume95"
int n = -1; lxn/97rA
try{ 1hbQ30
oSavedFile.write(b,nStart,nLen); exWQ~&
n = nLen; 1j2U,_-
} S'x ]c#
catch(IOException e) rJ/HIda
{ VwR\"8r3
e.printStackTrace (); !}=eXDn;A_
} [if(B\&
V9[_aP;
jOhAXe;~X{
return n; ` nX,x-UM
} )!(gS,
<$A,|m
>MYxj}I4{z
} H{cOkuy
FK BRJ5O
p\zqZ=s
/* FBE|pG7
**SiteInfoBean.java +Xg:*b9So
*/ c!@|yE,
package NetFox; x8lBpr
~&:-c v
\3vQXt\dM$
public class SiteInfoBean { A!Tl
RFw0u 0Nrz
7(/yyZQnZ
private String sSiteURL; //Site's URL g}~s"Sz
private String sFilePath; //Saved File's Path bK "I9T #
private String sFileName; //Saved File's Name DY`0 `T
private int nSplitter; //Count of Splited Downloading File 3]S*p ErY
:$I"n\
\O*ZW7?TJ
public SiteInfoBean() 6jpzyf=~
{//nSplitter的缺省值为5 +[}y` -t
//default value of nSplitter is 5 @<K<"`~H
this("","","",5); yz [pF
} aG1Fj[,
-~z@W3\
T4x%3-4;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .XgY&5Qk
{ ^E%R5JN
sSiteURL= sURL; -#%M,Qb
sFilePath = sPath; $mxG-'x%K
sFileName = sName; B1X&O d
this.nSplitter = nSpiltter; %)i&|AV"
m03dL^(
Vg62HZ |
} zd_N' :6
Ry[7PLn]
#>yOp *
public String getSSiteURL() |X{j^JP5
{ C.4(8~Y=~
return sSiteURL; 6$#,$aO
} |kmP#`P~
Jk{SlH3'
$.C\H,H
public void setSSiteURL(String value) H@- GYX"4
{ QXj#Brp
sSiteURL = value; ~{DJ,(N"n
} {"jtR<{)
@o[ZJ4>*
m 70r'b]
public String getSFilePath() a[;L+
{ N5 sR
return sFilePath; AXcmN
} pI f6RwH}%
T Tbe{nb
U/FysN_N!
public void setSFilePath(String value) 54{E&QvL8o
{ UR'v;V&Cb\
sFilePath = value; koB'Zp/FaY
} *v#V%_o
RAa1^Qb
TT3 6Y
public String getSFileName() bV:<%l]
{ b\^DQZmth
return sFileName; RH,x);J|
} -[!t=qi
2KO`+
9qa/f[G
public void setSFileName(String value) &y0GdzfQd
{ ^vm6JWwN0B
sFileName = value; "E<+idoz
} v2gk1a&
BZLIi O
.{eMN[ n@
public int getNSplitter() ]@y%j'e
{ uPho|hDp
return nSplitter; Y'1 KH}sH
} L5UZ@R,
!Th5x2
bOU"s>?
public void setNSplitter(int nCount) Sa)sDf1+`
{ aid1eF
nSplitter = nCount; ,J2qLH1
} NPv.7,
} w\[l4|g`
?9?A)?O<j~
P,zQl;
/* /7#MJH5b6
**Utility.java :}36;n<['
*/ {1=|H$wKg
package NetFox; ?(zCv9Pg
AP z"k?D0
tvno3"
public class Utility { 3AENY@*
/\Cf*cJ
{a\! 1~
public Utility() 1mHS -oI9J
{ f4,|D |
pC,Z=+:
J e|
} 3ouy-SQ
k)z>9z%D
//线程睡眠 ;jx[ +
public static void sleep(int nSecond) ^?]-Q*w3Qs
{ a/s5Oit2'X
try{ &kvmLOI
Thread.sleep(nSecond); vx7=I\1
} ic}TiTK
catch(Exception e) Uufig)6
{ ?zP 2
e.printStackTrace (); t+d7{&B
} |d~'X%b%
} M^OYQf
^6{op3R_
//日志 <!G\%C
public static void log(String sMsg) gP|-A`y
{ ,gpEXUp\
System.err.println(sMsg); {m3#1iV9
} J:'_S `J
z80(+`
y5c\\e
public static void log(int sMsg) k:V9_EI=
{ hl0X,G+@
System.err.println(sMsg); mw^>dv?
} uDJ;GD[yc
} >Mh\jt\
fp(zd;BSQ
$;(@0UDE
/* ab9ecZ
**TestMethod.java Y|wjt\M
*/ LRWM}'.s
package NetFox; [X /s^42
&:ZR% f
YH+(N
public class TestMethod { ) x+edYw
l-nH
_U LzA
public TestMethod() sMVk]Mb
{ ///xx/weblogic60b2_win.exe vP#*if[V5
try{ 7l/ZRz}1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S8kzAT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *pD|N
SiteFileFetch fileFetch = new SiteFileFetch(bean); N3lz-vP-
fileFetch.start(); o(DG 3qk
} DC/Czkv9
catch(Exception e){e.printStackTrace ();} :_xfi9L~W0
dg~lz80
WC=d@d)M
} Vh;|qF 9
vm;%713#1
n8)&1 q?V
public static void main(String[] args) KX;JX*)J
{ J,?F+Qji&=
new TestMethod(); U8NX%*oW
} )HI\T];
} m3o -p
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