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)); / v";u)
} W<J".2D
for(int i=0;i<nEndPos.length-1;i++) aBo8?VV]8
{ ]_cBd)3P}
nEndPos = nStartPos[i+1]; YeN /J.R
} ttEQgkd`
nEndPos[nEndPos.length-1] = nFileLength; Z3:M%)e_u$
} I6bekOvP
} G8c 8`~t
Irk@#,{<
HPc7Vo(
//启动子线程 deD%E-Ja
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r"yA=d'c
for(int i=0;i<nStartPos.length;i++) JsNqijVC
{ F[q:jY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ye-o'%{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0_Gi1)
nStartPos,nEndPos,i); +f{CfWIKs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .'3&!#3
fileSplitterFetch.start(); JNQiCK,)}M
} l `D>h2]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [kdt]+'+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F-!,U)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7qfo%n"
nEndPos = " + nFileLength); X!+#1NPM
// fileSplitterFetch[nPos.length-1].start(); vmI2o'zi
h@{U>U7
s|7(VUPL
//等待子线程结束 71AR)6<R
//int count = 0; {`Ekv/XWa
//是否结束while循环 yY,O=yOjq
boolean breakWhile = false; l,FK\
dXAKk[uf
Kjbz\~
while(!bStop) y`"~zq0D
{ ~7Ji+AJA
write_nPos(); @"BvyS,p
Utility.sleep(500); IR*g>q
breakWhile = true; goYRA_%cX
a );>
_dCsYI%
for(int i=0;i<nStartPos.length;i++) n@pm5f
{ `v*UY
if(!fileSplitterFetch.bDownOver) .&:GOD
{ GA19=gow
breakWhile = false; bM]\mo>z<
break; @(XX68
} #UR4I2t*
} wRgh`Hc\}
if(breakWhile) t`b>iX%(1t
break; &3x \wH/_
cY+vnQm
y %dUry%>
//count++; Fs^d-I
//if(count>4) "Aw| 7XII
// siteStop(); \;0J6LBc
} ?Ji.bnfK
I(6k.PQ
~z)diF<
System.err.println("文件下载结束！"); :t &ib}v
} R|PFGhi6"A
catch(Exception e){e.printStackTrace ();} p5<2tSD
} (2He]M\
fH_G;#q
xPa>-N=*
//获得文件长度 JpVV0x/Q/_
public long getFileSize() 2ql7*g?Uq@
{ +PC<#
int nFileLength = -1; K&(}5`H0=
try{ "yR56`=
URL url = new URL(siteInfoBean.getSSiteURL()); 9/$D&tRN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wAHW@q9CK
httpConnection.setRequestProperty("User-Agent","NetFox"); .r9-^01mG
28l",j)S
],ow@}
int responseCode=httpConnection.getResponseCode(); ,BM6s,\
if(responseCode>=400) 9*!C|gC9Ia
{ <v<TsEI
processErrorCode(responseCode); nQ\ +Za==
return -2; //-2 represent access is error lQs|B '
} bP;cDQ(g
8i!~w 7z
.lMIJN&/
String sHeader; zh5{t0E}C
76[O3%
9XGzQ45R
for(int i=1;;i++) F{*S}&q*)o
{ &*TwEN^h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); du2q6"
//Utility.log(in.readLine()); iqecm]Z0
sHeader=httpConnection.getHeaderFieldKey(i); (5@9j
if(sHeader!=null) HR'r~ #j
{ 5TlPs_o
if(sHeader.equals("Content-Length")) '>:mEXK}w
{ sa\v9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xwxMVp`|o
break; ybBLBJb
} XcJ'w
} O@U[S.IK
else ?9qA"5
break; J~z;sTR
} EUdu"'=4a
} 7+aTrE{
catch(IOException e){e.printStackTrace ();} "rz|sbj
catch(Exception e){e.printStackTrace ();} y}jX/Ln
Va"_.8n|+
M 7j0&>NTG
Utility.log(nFileLength); x;NCW
?'H);ou-p
/kGRN@
return nFileLength; pyK|zvr-r
} ua(y! Im
A:3bL: ;t
VNx|nP&
//保存下载信息（文件指针位置） 8ID fYJ
private void write_nPos() 0*^)n&O
{ SJ1 1LF3)
try{ i70TJk$fs
output = new DataOutputStream(new FileOutputStream(tmpFile)); >V:g'[b
output.writeInt(nStartPos.length); (80#{4kl
for(int i=0;i<nStartPos.length;i++) -d\O{{%>.z
{ o"@y=n/
// output.writeLong(nPos); 2BOe,giy
output.writeLong(fileSplitterFetch.nStartPos); F,#)8>O
output.writeLong(fileSplitterFetch.nEndPos); Yo:l@(
} 8:,E=swe
output.close(); -A}*Aa'\
} 8XwAKN:f
catch(IOException e){e.printStackTrace ();} uV<I!jyI
catch(Exception e){e.printStackTrace ();} 2U,O e9
} G.K3'^_
| ]`gps
U6qv8*~
//读取保存的下载信息（文件指针位置） lp5`Kw\
private void read_nPos() Fz7(Kuc
{ [X:mmM0gd
try{ 'pOtd7Vr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R}4o{l6
int nCount = input.readInt(); pYV$sDlD
nStartPos = new long[nCount]; q4vu r>m6
nEndPos = new long[nCount]; 10dVV[=
for(int i=0;i<nStartPos.length;i++) +F ~;Q$T
{ .:,RoK1
nStartPos = input.readLong(); lpkg(J#&
nEndPos = input.readLong(); T{u!4Yu
} dwks"5l
input.close(); LH..8nfl
} %7BVJJp2
catch(IOException e){e.printStackTrace ();} ?}sh@;]*h
catch(Exception e){e.printStackTrace ();} MjC;)z
} Ky`rf}cI>
+=%13cA*U
[wl:"rm
private void processErrorCode(int nErrorCode) .['@:}$1
{ [6qa"Ie
System.err.println("Error Code : " + nErrorCode); ~T<#HSR`
} HGmgQ>q@M$
BM{GSX
YMP:T?vMVh
//停止文件下载 ^a|$z$spf
public void siteStop() /_E:sI9(
{ $enh>!mU
bStop = true; u4B,|_MK
for(int i=0;i<nStartPos.length;i++) *!UY;InanX
fileSplitterFetch.splitterStop(); 5=Mm=HyI2
|jm|/{lc
3ydOBeY
} w\=zTHo88
} 13Ga #
//负责部分文件的抓取 eN{[T PPCq
**FileSplitterFetch.java yyh L]Uq"=
*/ 8%JxXtWW`
package NetFox; (5{|']G
IjN3 jU
';??0M
import java.io.*; e;pVoRI
import java.net.*; vTjgW?9
R|H9AM ~E
<5/r
public class FileSplitterFetch extends Thread { h{.KPK\
2}]6~i
AY:3o3M
String sURL; //File URL 8 f%@:}H
long nStartPos; //File Snippet Start Position =25qY"Mf
long nEndPos; //File Snippet End Position ?RvXO'ml
int nThreadID; //Thread's ID VE^NSkOa&
boolean bDownOver = false; //Downing is over _:0<]<x?
boolean bStop = false; //Stop identical C1P{4 U
FileAccessI fileAccessI = null; //File Access interface 7P9n. [
1Nw&Z0MI
I"@X~Y7}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y|q4d(P.
{ d9|dHJf
this.sURL = sURL; #/@U|g
this.nStartPos = nStart; ([UuO}m-
this.nEndPos = nEnd; AL! ^1hCF
nThreadID = id; c&)H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $G5m/[KDI
} j11\t
,Ihuo5>/z
[6BLC{2
public void run() /7*jH2
{ zB\g'F/
while(nStartPos < nEndPos && !bStop) 8-cG[/|0
{ sl|s#+Z
_3tHzDSG#
m3 ;
try{ wq_c^Ioy
URL url = new URL(sURL); 7Upm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C=@BkneQ
httpConnection.setRequestProperty("User-Agent","NetFox"); zy4AFW
String sProperty = "bytes="+nStartPos+"-"; &d`Umm]
httpConnection.setRequestProperty("RANGE",sProperty); rMSB|*_
Utility.log(sProperty); xPb;_~
j2lo~J)
F}0QocD
InputStream input = httpConnection.getInputStream(); gB&]kHLO
//logResponseHead(httpConnection); z=!$3E ecr
E xKH%I
nFW^^v<
byte[] b = new byte[1024]; vX)6N#D!
int nRead; MjE.pb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EG&^;uU
{ n=r}jRH1
nStartPos += fileAccessI.write(b,0,nRead); :7Rs$ -*Uk
//if(nThreadID == 1) (U2G"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )(*A1C[
} Di9yd
D/V.o}X$
*)ed(+b
Utility.log("Thread " + nThreadID + " is over!"); J:f>/
bDownOver = true; hiaj!&+Q
//nPos = fileAccessI.write (b,0,nRead); <,Sy:>:"
} 0ang~_
catch(Exception e){e.printStackTrace ();} /OgXNIl]
} r4JXbh6Tt
} ixBM>mRK
<Nvw w
-6~*:zg,
//打印回应的头信息 Sn.I ]:l
public void logResponseHead(HttpURLConnection con) ) EEr?"
{ 7t5X
for(int i=1;;i++) 7oF`Os+U
{ oF.Fg<p(
String header=con.getHeaderFieldKey(i); N ED`GU
if(header!=null) Cd'P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I.R3?+tZ
Utility.log(header+" : "+con.getHeaderField(header)); 10}oaL S
else PZNo.0M70
break; vbqI$F[s
} w?C_LP
} )g:UH Ns
[2 2IF
h|=^@F_\`
public void splitterStop() HCHP15otfe
{ E}k#-+u<S4
bStop = true; eN/sW!:P|
} sl6p/\_w
{,IWjt &>
?MKf=!w
} P)1@HDN==
2@08V|
`"AjbCL
/* }S*6+4
**FileAccess.java FPaj p
*//文件访问(定位，写) -J[zJ4z#
package NetFox; *^Zt5 zk
import java.io.*; t8i"f L
gywI@QD%#
[.6>%G1C
public class FileAccessI implements Serializable{ (&x~pv"+
:m#vvH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MFW?m,It)
RandomAccessFile oSavedFile; E>4#j PK
long nPos; ~pzaX8!
W:(:hT6`j9
Lom%eoH)
public FileAccessI() throws IOException 32~Tf,
{ e"r}I!.
this("",0); /lr RbZ
} KG>.7xVWV7
6sP;O,UX
~|DF-t V
public FileAccessI(String sName,long nPos) throws IOException LvWU %?
{ GZZLX19sq
oSavedFile = new RandomAccessFile(sName,"rw"); zNE!m:s
this.nPos = nPos; q{U -kuui
oSavedFile.seek(nPos); OzO_E8Kb\
} ]XPGlM
d[~c-G6
|o!<@/iH=
public synchronized int write(byte[] b,int nStart,int nLen) E*(Q'p9C
{ GGJ_,S*
int n = -1; _'I9rGlx3
try{ n:*+pL;
oSavedFile.write(b,nStart,nLen); Ne^#5T
n = nLen; jb7=1OPD_
} 'Fonn
catch(IOException e) <ht>>
{ Phb<##OB
e.printStackTrace (); N23s{S t
} }rO4b>J
MO _9Yi
8z/^Ql
return n; d\)v62P
} ]ei]) JI
G x,D'H'
1c}'o*K_%
} nn=JM7e\9
1Rczf(,aT
=x7ODBYW^
/* Ev^Xs6 }"
**SiteInfoBean.java dHp6G^Y
*/ L1F){8[
package NetFox; vo::y"
{#[a4@B0
"Q/3]hc.
public class SiteInfoBean { =pk'a_P8-
CC)9Ks\
y.O? c&!
private String sSiteURL; //Site's URL r p@=
private String sFilePath; //Saved File's Path i44:VR|
private String sFileName; //Saved File's Name \6lXsu;I.X
private int nSplitter; //Count of Splited Downloading File iEU(1?m2-
Etl7V
'@fk(~|
public SiteInfoBean() &>s(f-\8
{//nSplitter的缺省值为5 AoR`/tr,
//default value of nSplitter is 5 &a|oJ'clz
this("","","",5); TM"-X\e~{
} <=zGaU,
IK W!P1
zu^ AkMc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $<aBawLZO
{ "|Pl(HX
sSiteURL= sURL; /C(L(X
sFilePath = sPath; fk"{G>&8
sFileName = sName; 3%P?1s
this.nSplitter = nSpiltter; "(xS[i
.H>Rqikj
S5d{dTPq
} q6ikJ8E8b
kl={L{r
5sE^MS1
public String getSSiteURL() {c J6Lq&
{ h)<R#xw
return sSiteURL; )ld7^G
} %/^d]#
#>,cc?H-
1z`,*eD7
public void setSSiteURL(String value) }UO,R~q~
{ `j(+Y
sSiteURL = value; T2->
} $?s^HKF~
s{IoL_PJP
7d<v\=J}
public String getSFilePath() z=fag'fzM
{ ew"Fr1UGYZ
return sFilePath; 7&QVw(:)M
} uqyf3bK
ryT8*}o
n (|>7
public void setSFilePath(String value) q-RGplx
{ |4c==7.
sFilePath = value; e56#Qb@$\
} ((5zwD
XgbGC*dQ
7*5ctc!dG
public String getSFileName() I,S'zHR
{ dL\8^L
return sFileName; Ax%BnkU
} NV gLq@F
~mp$P+M(%p
3(&.[o Z
public void setSFileName(String value) K]u|V0c
{ Lg?'1dg
sFileName = value; ~h@tezF
} U<t-LF3
<2Q@^
Y/^<t'o&
public int getNSplitter() n>4S P_[E7
{ S?{5DxilO
return nSplitter; '-vyQ^
} 3dbf!
VZ,T`8"
&8pXkD#A
public void setNSplitter(int nCount) 9,W-KM
{ Chua>p!$g
nSplitter = nCount; O)Qz$
} @( t:E`8
} z(WpOD
e?YbG.(E9
y#0w\/<
/* uaKB
**Utility.java 3wE8y&
*/ -b$OHFL
package NetFox; Q#N+5<]J)#
|z'?3?,~
2{CSH_"Z7
public class Utility { 64lEB>VNm
eTc`FXw`
v2{O67j} o
public Utility() k~R[5W|'
{ [FL I+;gY
, .I^ekF
2UF94
} mc'p-orAf
@"!SU'*
//线程睡眠 `/zt&=`VB
public static void sleep(int nSecond) %Let AR
{ 2FzS_\":I
try{ RV`j>1
Thread.sleep(nSecond); =M5M;
} P1wRt5
catch(Exception e) H1nQ.P]_
{ 0vp I#q
e.printStackTrace (); F4Uk+|]Bu
} 3\+p1f4
} ~N9-an
{9".o,
//日志 F29AjW86
public static void log(String sMsg) 1%"` =$q%
{ IFxI>6<&
System.err.println(sMsg); >#?: x*[
} d*$<%J
L_mqC(vn
G 7]wg>*
public static void log(int sMsg) Bx-,"Z \
{ zfb _ )
System.err.println(sMsg); c0&'rxi(B
} v|@n8ED|@K
} C8:"+;
YZRB4T9
wF8\
/* j\f$r,4
**TestMethod.java *]WXM.R8
*/ LFyceFbm
package NetFox; l7,qWSsnK
Zk UuniO
ok[=1gA#h
public class TestMethod { SAh054/St
v4_OUA>z,
}G+A_HF ^
public TestMethod() 5Kj4!Ai
{ ///xx/weblogic60b2_win.exe `uVW<z{l
try{ ;6nZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b:Kw_Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WN+Jf
SiteFileFetch fileFetch = new SiteFileFetch(bean); _|3TC1N$n
fileFetch.start(); I&8SP$S>J
} 2j7d$y*'
catch(Exception e){e.printStackTrace ();} %J7mZB9
v8bl-9DQ
xsDa!
} <C%-IZv$
(V.,~t@
$sF#Na4^
public static void main(String[] args) %8CT -mQ
{ \t# 9zn>
new TestMethod(); G.nftp(*}
} 5w)^~#'
} 9jGuelwN
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