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,RU8&
} l%<c6;
for(int i=0;i<nEndPos.length-1;i++) 6LM9e0oxy
{ Z,aGtJ.a'9
nEndPos = nStartPos[i+1]; %U?)?iZdL
} oMc1:=EG
nEndPos[nEndPos.length-1] = nFileLength; 40.AM1Z0f
} %nQmFIt
} %3G;r\|r]
P)1EA;
sX'nn
//启动子线程 *#h;c1aP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3Gd|YRtk
for(int i=0;i<nStartPos.length;i++) (\& 62B1
{ kzi|$Gs<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zlkWU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @L8;VSI
nStartPos,nEndPos,i); Z4@y?fv7s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xA-jvu9@
fileSplitterFetch.start(); =4>@8=JA
} OX3Xy7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %?dE{ir
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e5OVq ,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q|//Z
nEndPos = " + nFileLength); {US>)I
// fileSplitterFetch[nPos.length-1].start(); !*bdG(pK
oHsP?%U
OjATSmZ@@
//等待子线程结束 PL@7KDQ
//int count = 0; UABbcNW
//是否结束while循环 #(dhBEXPW;
boolean breakWhile = false; Q>%E`h
o9+Q{|r
WZK :.y
while(!bStop) %zflx~
{ OG}KqG!n
write_nPos(); ?O7iK<5N
Utility.sleep(500); @_Sp3nWdu
breakWhile = true; h2;l1G,
QgZJ`G--
vJThU$s-
for(int i=0;i<nStartPos.length;i++) ?*+1~m>
{ 7@a\*|K6
if(!fileSplitterFetch.bDownOver) [gn[nP9
{ vHc#m@4o
breakWhile = false; 3+zzi
break; `^%@b SE(
} Tk](eQsy.v
} PUKVn+h
if(breakWhile) d?}hCo=/Xq
break; #ovM(Mld
xVTo4-[p
UN(3i(d
//count++; A^L?_\e6
//if(count>4) PW)8aLU
// siteStop(); =mLeMk/7 w
} .hne)K%={y
hgwn> p:S#
oG\>--
System.err.println("文件下载结束！"); ^'YHJEK
} r0uJ$/!
catch(Exception e){e.printStackTrace ();} S}mm\<=1
} CjV7q y
$eMK{:$O
eI?HwP{m
//获得文件长度 K1-+A2snhV
public long getFileSize() y($EK(cb
{ 3P`WPph
int nFileLength = -1; >uW^.e "F
try{ -#OwJ*-U
URL url = new URL(siteInfoBean.getSSiteURL()); b=G4MZQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yx 3|G
httpConnection.setRequestProperty("User-Agent","NetFox"); q;No"_aAd
Hh\ 4MNl
MYu`c[$jZ
int responseCode=httpConnection.getResponseCode(); -)>(8f
if(responseCode>=400) ``6{T1fQS
{ 4UVW#Rw{
processErrorCode(responseCode); 1VGpq-4*j
return -2; //-2 represent access is error 5Kee2s?*
} j@CKO cn2
G g(NGT
yZ|+VXO
String sHeader; h,~tXj
$$\V2%v
;Rs.rl>;t/
for(int i=1;;i++) X&.:H~xS+
{ Nuo^+z E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WV@X@]U
//Utility.log(in.readLine()); Qxky^:B
sHeader=httpConnection.getHeaderFieldKey(i); _hWuAJ9Qy
if(sHeader!=null) yIWc\wv
{ 7|{ B#
if(sHeader.equals("Content-Length")) '9"%@AFxZ
{ {=qEBbM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [bsXF#
break; T:6K?$y?
} `ReGnT[
} 9p4%8WhJ
else X0!Bs-WFp
break; Enu!u~1]F
} 'H!V54 \j
} v` $%G
catch(IOException e){e.printStackTrace ();} W oWBs)E
catch(Exception e){e.printStackTrace ();} HmW=t}!
<c(&T<$
_TrZ'iL}T
Utility.log(nFileLength); N6WPTUQ1mF
}a'cm!"
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return nFileLength; )O9fhj)
} WqR7uiCi
lS#7xh
X:U=MWc>
//保存下载信息（文件指针位置） }\>+H
private void write_nPos() H<$pHyxU
{ x\6];SXX
try{ JV&Zwbu
output = new DataOutputStream(new FileOutputStream(tmpFile)); <r_3obRC
output.writeInt(nStartPos.length); 5`{=`
for(int i=0;i<nStartPos.length;i++) r1+c/;TpZ
{ 9uKOR7.zbo
// output.writeLong(nPos); D/e&7^iK
output.writeLong(fileSplitterFetch.nStartPos); iQu^|,tHEM
output.writeLong(fileSplitterFetch.nEndPos); +)?,{eE|
} gji*Wq
output.close(); Qg[heND
} c5<kbe
catch(IOException e){e.printStackTrace ();} 7&h\l6}Yh
catch(Exception e){e.printStackTrace ();} >B`Cch/'U
} *B%y`cj|
zf`5>h|
-Sx0qi'%
//读取保存的下载信息（文件指针位置） 1]Gf)|
private void read_nPos() o T:j:n
{ h,]tQ#!s8
try{ z/)$D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]F !'M
int nCount = input.readInt(); ";756'>
nStartPos = new long[nCount]; JR])xPI`
nEndPos = new long[nCount]; ,tau9>!
for(int i=0;i<nStartPos.length;i++) cD5w| rm?i
{ ES^NBI j5P
nStartPos = input.readLong(); EN)YoVk
nEndPos = input.readLong(); KuIkul9^%
} E2h(w_l
input.close(); :2_0L
} nT_*EC<.
catch(IOException e){e.printStackTrace ();} F ~*zC`>Y
catch(Exception e){e.printStackTrace ();} p@vpd
} " 98/HzR
K1/ U (A
uFz/PDOZ@
private void processErrorCode(int nErrorCode) :wFb5"
{ fdN45in=>
System.err.println("Error Code : " + nErrorCode); "&@gX_%
} cLn;,u4
H3!,d`D.N
pi|\0lH6W
//停止文件下载 ]gb _Nv
public void siteStop() b*cW<vX}~
{ f+{c1fb>s
bStop = true; a:=q8Qy
for(int i=0;i<nStartPos.length;i++) $[)6H7!U)
fileSplitterFetch.splitterStop(); ThjUiuWe
@mvIt
_2wAaJvA
} joxS+P5#
} Tnf&pu#5
//负责部分文件的抓取 th5 X?so
**FileSplitterFetch.java C_6GOpl
*/ cR,'o'V/
package NetFox; $Vo/CZW7
8FAT(f//.
^!q 08`0
import java.io.*; r5D jCV"
import java.net.*; z`c%?_EK
0PYvey }[
G%xb0%oi]%
public class FileSplitterFetch extends Thread { 2O?Vr" A
g7.7E6%H
=n> iQS
String sURL; //File URL 3X,]=f@_
long nStartPos; //File Snippet Start Position vEu Ka<5
long nEndPos; //File Snippet End Position xylpiSJ
int nThreadID; //Thread's ID [Bl $IfU
boolean bDownOver = false; //Downing is over _`TepX R
boolean bStop = false; //Stop identical Rbx97(wK
FileAccessI fileAccessI = null; //File Access interface QIR4<]/
Su$18a"Bc
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }9{dR4hD
{ H|grbTv,
this.sURL = sURL; 7xX;MB&
this.nStartPos = nStart; `Af{H/qiI
this.nEndPos = nEnd; D."cQ<sxpN
nThreadID = id; ^`l"'6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l\q*%'Pe
} s@[C&v
f 1sy9nQs
sjkWz2]S
public void run() C4&U:y<ju
{ b7?U8/#'
while(nStartPos < nEndPos && !bStop) MDMtOfe|
{ }v_p gatC
szf"|k!
Zkf 3t>[
try{ *54>iO- c
URL url = new URL(sURL); ^</65+OT+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mle_*Gy8
httpConnection.setRequestProperty("User-Agent","NetFox"); r^?)F?n!
String sProperty = "bytes="+nStartPos+"-"; L!CX&
httpConnection.setRequestProperty("RANGE",sProperty); hB|H9+
Utility.log(sProperty); F?*Dr
h$E\2lsE
aK8bKlZe
InputStream input = httpConnection.getInputStream(); )B-MPuB
//logResponseHead(httpConnection); ^VSt9&
KC@k9e
Fpy6"Z?z
byte[] b = new byte[1024]; ^n\9AE3
int nRead; L9E;Uii0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l=oN X"l=
{ ZA*b9W
nStartPos += fileAccessI.write(b,0,nRead); 6Cz7A
//if(nThreadID == 1) <C7M";54-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5*s1qA0^
} sN}s61
<'PR;g^#
v7s]
Utility.log("Thread " + nThreadID + " is over!"); h Jfa_
bDownOver = true; A[sM{i~Z
//nPos = fileAccessI.write (b,0,nRead); `_NnQ%
} [VY8?y
catch(Exception e){e.printStackTrace ();} &/b?I `
} Nrab*K(][
} ET >S
[@,OG-"&
/>dB%*
//打印回应的头信息 r1[E{Tpz
public void logResponseHead(HttpURLConnection con) t_[M&
{ GM)\)\kNF
for(int i=1;;i++) 3::3r}g
{ DhtU]w}
String header=con.getHeaderFieldKey(i); Q3<bC6$r
if(header!=null) Hs:4I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m#5|J@]
Utility.log(header+" : "+con.getHeaderField(header)); sDLVYD
else Hmz=/.$
break; S5:"_U
} |i,zY{GI+2
} OqfhCNAY
Bo\a
WUE)SVf
public void splitterStop() =:xV(GK}
{ 'Z*\1Ci
bStop = true; u)q2YLK8
} e3yorQ][
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e.)yV'%L
} }};j2
1kB'sc3N!
x&hvFG3
/* Bi9 N
**FileAccess.java { 4_I7r
*//文件访问(定位，写) d-6sC@PB
package NetFox; 2ru*#Z#(
import java.io.*; f7EIDFX>pt
&^CL]&/
c]AKeq]
public class FileAccessI implements Serializable{ mhHA!:Y
rd&*j^?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8{}Pj
RandomAccessFile oSavedFile; ZI2K-z'e
long nPos; gmF_~"^34
Bo](n*i
p`E|SNt/W
public FileAccessI() throws IOException f"5lOzj`C
{ &y#\1K
this("",0); ^]#Ptoz^(l
} [OFTP#}c
Pi&fwGL
B|]t\(~$[
public FileAccessI(String sName,long nPos) throws IOException ,(@Y%UW:
{ 38x[Ad4%
oSavedFile = new RandomAccessFile(sName,"rw"); (c|$+B^*
this.nPos = nPos; Sah<sb=
oSavedFile.seek(nPos); }$&T O$LX
} mr{k>Un\
%:'1_@Ot2
@!L@UP0
public synchronized int write(byte[] b,int nStart,int nLen) bl:a&<F
{ |:7EJkKZ
int n = -1; FT*yso:X/
try{ 6SW|H"!!
oSavedFile.write(b,nStart,nLen); r)9i1rI+
n = nLen; _g^K$+F'}
} CI~hmL0
catch(IOException e) wS F!Xx0
{ #K<=xP
e.printStackTrace (); uZqu xu.
} z._C*c
?{@!!te@3v
i#@v_^q
return n; gqO%^b)6
} b.mjQ
TRr4`y%
BRo R"#'
} eLDL "L
a>)_ `m
OUBgBr
/* dN$D6*
**SiteInfoBean.java }6uV]V{
*/ X*0eN3o.
package NetFox; C)&gL=O*$
_-|yCo
tKs4}vW
public class SiteInfoBean { ;9!yh\\
|h^G$guw
vjs|!O=oH
private String sSiteURL; //Site's URL wa(Wit"-
private String sFilePath; //Saved File's Path T9<H%iF
private String sFileName; //Saved File's Name ;i-D~Np|
private int nSplitter; //Count of Splited Downloading File ^huBqEs
^V XXq
n7`.<*:
public SiteInfoBean() Sq?6R}q%
{//nSplitter的缺省值为5 eSvc/CU
//default value of nSplitter is 5 ;4S [ba1/
this("","","",5); ?v)"%.
} $X.'W\o|
(zM+7tJH
j-I6QUd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /\3XARt
{ `F-Dd4B
sSiteURL= sURL; T,xVQ4J?
sFilePath = sPath; fr,CH{Uq
sFileName = sName; 6gg#Z
this.nSplitter = nSpiltter; <750-d!
<@x+N%C
RBv=
} mk[d7Yt{O
#/XK&(X
}'w^<:RSy
public String getSSiteURL() m|#(gX|F
{ ]mD=Br*r~
return sSiteURL; 8ZNd|\
} e$/Zb`k
qN`]*baS
x%:>Ol
public void setSSiteURL(String value) !cFE^VM_;
{ ,h^;~|GT
sSiteURL = value; @WDqP/4
} X/;"CM
R<0!?`b
,39$iHk
public String getSFilePath() zhR_qW+
{ 6Ymo%OT
return sFilePath; V)?x*R*T)
} N?U&(@p
`MpC<sit
PE;0 jgsiI
public void setSFilePath(String value) qI V`zZc
{ 2)I'5?I
sFilePath = value; z5o9\.y({
} Fb<$#t
p-(ADQS
9^Vx*KVrU
public String getSFileName() w_z^5\u0
{ a,0o{*(u$
return sFileName; ?w5nKpG#RI
} )Ido|!]0d
si mX
q2j}64o_S
public void setSFileName(String value) `aWwF} +Y
{ 2h? r![
sFileName = value; fY\tvo%
} 4K?H-Jco
{If2[4!z
^)0{42!]
public int getNSplitter() {</$ObK
{ )S;Xy`vO
return nSplitter; `w+9j-
} 3sg)]3jm2
O,xAu}6f+
?BWvF]p5/
public void setNSplitter(int nCount) _^2[(<Gmv
{ $85o%siS'
nSplitter = nCount; 3xCA\*
} C;:1CK
} CyBM4qyH
23n8,} H,
* SON>BSF
/* Kp=3$&
**Utility.java $d??(
*/ )i6U$,]
package NetFox; $b 71
. =foXN
ks`
public class Utility { CR<pB)F?a
)'I<xx'1
PS<tS_.
public Utility() W-ND<=:Up
{ ,"MUfZ
W9:{pQG
vM3|Ti>a'
} eS# 0-
6~Oje>w;
//线程睡眠 Vqp.jF1|
public static void sleep(int nSecond) Sdu@!<?B
{ uxJiec`&
try{ [\M?8R$)
Thread.sleep(nSecond); ! {o+B^^
} PM?Ri^55<L
catch(Exception e) ` Ehgn?6'
{ }Yl8Q>t
e.printStackTrace (); "s6_lhu=E7
} bg3jo1J
} H><mcah
%Ja{IWz9L
//日志 ]A<u eM
public static void log(String sMsg) EV,NJ3V
{ yURh4@
System.err.println(sMsg); !+VN
} !J?=nSu
FEi,^V
Ly/~N/<\
public static void log(int sMsg) _j<M}
{ iuk8c.TAR
System.err.println(sMsg); mS;Q8Crh
} r_<i*l.
} \C\y'H5
A)a+LW'=u
cz~11j#
/* Ecl7=-y
**TestMethod.java "7g8 d
*/ V'hz1roe
package NetFox; !<^j!'2
@DKl<F
pO+wJ|f
public class TestMethod { 5Fm?,^
<?@46d?C
Uo)<_nG
public TestMethod() ~map5@Kd
{ ///xx/weblogic60b2_win.exe nPX'E`ut-V
try{ [&kk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cZF;f{t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v&,VC~RN-J
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]T$w7puaJ
fileFetch.start(); QMpA~x_m
} lfhKZX
catch(Exception e){e.printStackTrace ();} DmA!+
"1TM
qvE[_1QCc
} ['`'&+x&!
;Wm)e~`,
`ZV'7|
public static void main(String[] args) U5%]nT"[]
{ t"Rf67
new TestMethod(); mpJ_VS`
} ?Lb7~XKt\
} Ps5wQaS
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