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)); +' .o
} bWZzb&
for(int i=0;i<nEndPos.length-1;i++) eQ=6< ^KZ
{ 9A\\2Zz6F
nEndPos = nStartPos[i+1]; AC?a:{./
} +KP&D.wIo
nEndPos[nEndPos.length-1] = nFileLength; 2>^jMln
} ).MV1@s
} oPF n`8dQ
(S&D
`cRRdD:dA
//启动子线程 ORIXcj]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;s$ P?('
for(int i=0;i<nStartPos.length;i++) ECuNkmUI
{ *E/CNMn=E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EPEn"{;U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I$fm"N
nStartPos,nEndPos,i); =u5( zaBe
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4(8BWP~.y2
fileSplitterFetch.start(); O<?.iF%
} 7VfPS5se
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U\"FYTC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v dU)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ofCN[u
nEndPos = " + nFileLength); <M,=(p{
// fileSplitterFetch[nPos.length-1].start(); ,esUls'nz'
[O3)s]|
z{U^j:A
//等待子线程结束 % )}rQqQ
//int count = 0; (/_w23rr
//是否结束while循环 [](] "r
boolean breakWhile = false; C'joJEo
O F?o
^`9O$.'@
while(!bStop) .H86f !=
{ A] f^9F@
write_nPos(); %^;rYn3
Utility.sleep(500); *adwCiB
breakWhile = true; 9%?a\#C
-JdNA2P
h,i=Y+1
for(int i=0;i<nStartPos.length;i++) 2)|G%f_lS
{ Qf@ha
if(!fileSplitterFetch.bDownOver) +,4u1`c|$
{ A4TW`g_zm
breakWhile = false; U~8, N[
break; Cuom_+wV&
} $69d9g8-(!
} p!`S]\XEB
if(breakWhile) D+4$l+\u
break; G,@Jo[e
/+?eSgM/
kclZ+E
//count++; iGIry^D
//if(count>4) Rw`64L_
// siteStop(); di~ [Ivw
} Lr(My3vF8q
*V@t]d$=#
%$+bO/f
System.err.println("文件下载结束！"); O|&SL03Z8
} aydf# [F
catch(Exception e){e.printStackTrace ();} *#o2b-[V
} ])Z p|?Y
W!b'nRkq
,+'VQa"]
//获得文件长度 "bvob G
public long getFileSize() kOv37c'
{ +)*oPSQ5
int nFileLength = -1; o?wEX%
try{ "lBYn2W
URL url = new URL(siteInfoBean.getSSiteURL()); T$o;PJc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /9 |BAQ:v;
httpConnection.setRequestProperty("User-Agent","NetFox"); s[u*~A
U%aDkC+M
RnUud\T/
int responseCode=httpConnection.getResponseCode(); hJ*#t<.<P;
if(responseCode>=400) >d^DN;p
{ dPF*G$
processErrorCode(responseCode); .2*h!d)E
return -2; //-2 represent access is error 7_5-gtD
} Mdy4H[Odq
ZtOv'nTD
1,pPLc(
String sHeader; VJ-To}
cwI3ANV
bMN]co
for(int i=1;;i++) Lz`_&&6
{ "V<7X%LIX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _16r8r$V
//Utility.log(in.readLine()); *XluVochrb
sHeader=httpConnection.getHeaderFieldKey(i); NV;T*I8O
if(sHeader!=null) L=kETJ:g
{ $`"$ZI6[
if(sHeader.equals("Content-Length")) 8:"s3xaO3
{ md/NMC \
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x UTlM
break; r<_qU3Eaj
} l#3jJn
} \S)cVp)h
else 7Q #A
break; fOz.kK[]
} \_t[\&.a}
} s#)0- Zj
catch(IOException e){e.printStackTrace ();} o(oD8Ni
catch(Exception e){e.printStackTrace ();} Md>9Daa~
XOPiwrg%p
]?0]K!7Ea
Utility.log(nFileLength); n<DZb`/uHZ
@6{F4
W%<z|
return nFileLength; *~8g:;u
} ffem7eQ
[g$IN/o%
*4[P$k$7
//保存下载信息（文件指针位置） V_jGL<X|
private void write_nPos() SnGXEQ
{ $x(p:+TI\4
try{ v)LSH;<
output = new DataOutputStream(new FileOutputStream(tmpFile)); r/RX|M
output.writeInt(nStartPos.length); v=x)]<E"_
for(int i=0;i<nStartPos.length;i++) XiAflO
{ lO8GnkLE
// output.writeLong(nPos); H8qWY"<Vd
output.writeLong(fileSplitterFetch.nStartPos); )Xice=x9
output.writeLong(fileSplitterFetch.nEndPos); :Oi}X7\
} a*!9RQ
output.close(); 9Q&]5|x
} 6'jgjWEe3&
catch(IOException e){e.printStackTrace ();} 4+F@BxpB
catch(Exception e){e.printStackTrace ();} t9&=; s
} m%)S<L7 l
p+^K$w^Cs
hCB _g
//读取保存的下载信息（文件指针位置） X@%4N<
private void read_nPos() zTfl#%
{ DfVSG1g
try{ 4\14HcTcK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I\('b9"*
int nCount = input.readInt(); fs8C ^Ik>~
nStartPos = new long[nCount]; "VA'W/yv!
nEndPos = new long[nCount]; R{{?wr6b$
for(int i=0;i<nStartPos.length;i++) ho}G]y
{ [.nkNda5)v
nStartPos = input.readLong(); (O'O#AD
nEndPos = input.readLong(); zz-X5PFn
} 8n/[oDc]
input.close(); Nd**":i$
} =Kt!+^\")
catch(IOException e){e.printStackTrace ();} ;tfGhHpQn
catch(Exception e){e.printStackTrace ();} @Zfg]L{Lr
} 6\6g-1B`
DU:+D}vl
#QiNSS
private void processErrorCode(int nErrorCode) %m "9 =C
{ E4xybVo@
System.err.println("Error Code : " + nErrorCode); MG3xX;
} - *xn`DH
14p{V}f3
Mqm9i
//停止文件下载 Y$FhV~m
public void siteStop() gTg[!}_;\N
{ {1'M76T
bStop = true; cEEnR1
for(int i=0;i<nStartPos.length;i++) F& ['w-n%
fileSplitterFetch.splitterStop(); /5Xt<7vm8
%TzdpQp"
phy:G}F6%
} Ss'Dto35Q
} |kqRhR(Ei
//负责部分文件的抓取 (YHK,aC>u
**FileSplitterFetch.java eyG[1EEU
*/ ]O&yy{yYK
package NetFox; h BzZJ/jn
! Y'~?BI
|6~ Kin
import java.io.*; ^aY,Wq
import java.net.*; ?r^>Vk}
*ub"!}$st
c1g'l.XL 3
public class FileSplitterFetch extends Thread { (_eM:H=e>
^1X 6DH`
gA&`vnNP
String sURL; //File URL sh}eKwh
long nStartPos; //File Snippet Start Position 'HvJ]}p
long nEndPos; //File Snippet End Position GX%r-
int nThreadID; //Thread's ID &M2fcw?
boolean bDownOver = false; //Downing is over $K_-I8e|
boolean bStop = false; //Stop identical VQn]"G(`
FileAccessI fileAccessI = null; //File Access interface j15t8du&O
36yIfC,
/mnV$+BE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M3H^s_
{ v|2+7N:[;
this.sURL = sURL; gOkum_
this.nStartPos = nStart; b R9iqRbn
this.nEndPos = nEnd; {\ogw0X
nThreadID = id; >C}KSyV;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zq]:.s
} d>x(Bj6
Lg+cHaA
>!#or- C
public void run() Ej'N!d.
{ 6KKQ)DNu_
while(nStartPos < nEndPos && !bStop) ]?~[!&h
{ "qw.{{:tf
BV]$= e'
#=I5_u
try{ u7bji>j
URL url = new URL(sURL); nLnzl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '#CYw=S+
httpConnection.setRequestProperty("User-Agent","NetFox"); PfJfa/#pA
String sProperty = "bytes="+nStartPos+"-"; TU?$yNE
httpConnection.setRequestProperty("RANGE",sProperty); {-L}YX"Bh
Utility.log(sProperty); "mAMfV0
VPOp#;"%
VBe&of+
InputStream input = httpConnection.getInputStream(); }1Pv6L(o)
//logResponseHead(httpConnection); jW]Fx:mQi
P.O/ZW>g
0]l9x}
byte[] b = new byte[1024]; BDPF>lPf<
int nRead; vPx#TXY=b}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;f2<vp;U
{ CV*
nStartPos += fileAccessI.write(b,0,nRead); H:X(><J
//if(nThreadID == 1) e)]DFP[n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /UiB1-*b
} iI!g1
YG>6;g)Zm
0<]]q[pr
Utility.log("Thread " + nThreadID + " is over!"); fl<j]{*v
bDownOver = true; #\MkbZc d
//nPos = fileAccessI.write (b,0,nRead); IdciGS6t
} >~@ABLp6
catch(Exception e){e.printStackTrace ();} +<f!#4T
} avxI%%|
} QykHB k
pcPRkYT[M
Hu$JCB-%
//打印回应的头信息 wy?Hp*E
public void logResponseHead(HttpURLConnection con) @gihIysf
{ (:|1h@K/R
for(int i=1;;i++) "oT]_WHqo
{ =<z~OE'lV
String header=con.getHeaderFieldKey(i); BHZSc(-o
if(header!=null) I7jIA>ZZi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'jBtBFzP-
Utility.log(header+" : "+con.getHeaderField(header)); (.~'\@
else =B ts
break; j9 &0/ ~/
} mv1|oFVW
} Cj#?Z7}z
*jo1?
)iCg,?SSw=
public void splitterStop() :*)b<:4
{ k1;Jkq~
bStop = true; [N1[khY`
} UQCond+K
*AA78G|
fDZnC Fa
} fh@/fd
u&$1XZ!es
B \>W
/* ^j]"5@f
**FileAccess.java `-<m#HF:)d
*//文件访问(定位，写) Bt"*a=t;
package NetFox; ]`eJSk.
import java.io.*; N"/be
juBzpQYj
X$ 76#x
public class FileAccessI implements Serializable{ )LE#SGJP
_<l9j;6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @wW)#!Mou
RandomAccessFile oSavedFile; I}1<epd ,
long nPos; }3y Q*<
Ui;PmwQc&
,\E5et4
public FileAccessI() throws IOException UJGmaE
{ a8r+G]Z
this("",0); StM)lVeF
} pqxBu
DP4l %2m0
0/?=FM>
public FileAccessI(String sName,long nPos) throws IOException k{pn~)xg
{ 3Tr}t.mt
oSavedFile = new RandomAccessFile(sName,"rw"); ? p^':@=
this.nPos = nPos; @!s(Zkpev
oSavedFile.seek(nPos); &6@e9ff0
} }}~ t!/x
B,RHFlp{
~n!7 ?4%U
public synchronized int write(byte[] b,int nStart,int nLen) C~:!WRCz
{ iVb#X#
int n = -1; wq`\p['Q,
try{ _JXb|FIp
oSavedFile.write(b,nStart,nLen); -Hu]2J)
n = nLen; ,Y2){8#l
} J|[`8 *8
catch(IOException e) Ov8{ny
{ px.]m-
e.printStackTrace (); aFwfF^\(|,
} fO$~jxR.
cLCzLNyKl
p4I6oS`/.
return n; 8??%H7~
} AJ-~F>gn
<D{_q.`vA
+G>;NiP_
} Gzu $
KoO\<_@";
3?oj46gP
/* ppo\cy;
**SiteInfoBean.java jYJfo<
*/ $)Pmr1==
package NetFox; |&a[@(N:zf
^)|1T#Tz
"M5&&\uT
public class SiteInfoBean { Og3bV_,"
(_O_zu8_
9:jZ3U
private String sSiteURL; //Site's URL cE0Kvqe`
private String sFilePath; //Saved File's Path Ok2>%e
private String sFileName; //Saved File's Name >QM$ NIf@
private int nSplitter; //Count of Splited Downloading File wXxk+DV@
~",,&>#[K
)t$|'c}
public SiteInfoBean() dsJHhsu6
{//nSplitter的缺省值为5 k!6wVJ|_Y
//default value of nSplitter is 5 nFfwVqV
this("","","",5); rC!~4xj-
} Q!dNJQpb
"Hw%@
1ssEJ;#s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r)SwV!b
{ /R44x\nhr
sSiteURL= sURL; L(!mm
sFilePath = sPath; ^atBf![
sFileName = sName; 27Ve$Q8]v
this.nSplitter = nSpiltter; v J.sa&\H
NP*M#3$[
^zr]#`@G
} B?tO&$s
Z*(lg$A9M
tkGJ!aUt
public String getSSiteURL() 'F@#.Op`
{ ]1<O [d
return sSiteURL; >HXmpu.O
} +k4SN
h&6v&%S/L
*m[ow s
public void setSSiteURL(String value) <C9_5Ce~
{ 8L7ZWw d
sSiteURL = value; #7A_p8
} hup<U+p
zbDM+;
' Z}/3 dp
public String getSFilePath() Gp/yr
{ q={\|j$X
return sFilePath; ]}&f<X
} $lMEZt8A
r%/*,lLO
H]7;OM/g
public void setSFilePath(String value) 3yfq*\_uXw
{ a jCx"J
sFilePath = value; ^#4?v^QNh
} ?#LbhO*
4F+n`{~
kt;| $
public String getSFileName() 2$O@T]
{ 93npzpge
return sFileName; 6Q._zk
} # N.(ZP
iPxhDn<B
3S'juHTe
public void setSFileName(String value) x`vIY-DS
{ *SX'Or,
sFileName = value; lll]FJ1
} H0YxPk)
kgvB80$4
I~$LIdzw
public int getNSplitter() ,/;mK_6
{ U8z$=Wo
return nSplitter; I%NPc4p
} |6pNe T[
ec4jiE
7lvUIc?krW
public void setNSplitter(int nCount) l ^*GqP5
{ /IS j0"/$
nSplitter = nCount; KGclo-,
} Uk02VuS
} jy] hP?QG
Dm j^aFB0|
F-)lRGw
/* <}3c%Q1
**Utility.java %7PprN0>
*/ 6.Nu[-?
package NetFox; >a;^=5E
h7-!q@
IwIk;pB O
public class Utility { .Y%)&
nL+*-R!R
Hb3+$vJ^
public Utility() Q)c$^YsI
{ BHE((3
a<%WFix
28;D>6c
} _$me.
}*~EA=YN;
//线程睡眠 7 N?x29
public static void sleep(int nSecond) `MgR/@%hr
{ 4-4lh TE(
try{ C^S?W=1=w
Thread.sleep(nSecond); X3DXEeBEL
} &X +Qi
catch(Exception e) @+VvZc2Y
{ _M+'30
e.printStackTrace (); \fphM6([RK
} \#[W8k<Z
} )>atoA
EdA_Hf
//日志 #dDsI]E)
public static void log(String sMsg) ~(tZW
{ K h9$
System.err.println(sMsg); ,|_ewye
} :".:Wd
ObIi$uJX
TR,,=3n
public static void log(int sMsg) J_s?e#s
{ =z]&E 78Y
System.err.println(sMsg); K,[g<7X5
} 2*Uwp;0
} aTs5^Kh')
f- pt8
:<=!v5 SK
/* 0K'lr;
**TestMethod.java <JHU*Z
*/ V; 1r
package NetFox; rm>;B *;
v#.FK:u}
*$x/(!UE
public class TestMethod { >\K<q>*
/d5_-AB(v
a\\B88iRRZ
public TestMethod() 4@|K^nT`
{ ///xx/weblogic60b2_win.exe -vI?b#
try{ .b]g#Du=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5j`"@C5;O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l/yLSGjM
SiteFileFetch fileFetch = new SiteFileFetch(bean); EA2BN}
fileFetch.start(); |H5){2V>K
} rd\mFz-SB
catch(Exception e){e.printStackTrace ();} []0`>rVq
6hYv
2](R}
} %4cUa| =?
4hztYOhJ{
geWis(#J
public static void main(String[] args) ]Ole#Lz}Q
{ /`0*!sN*5
new TestMethod(); AqvRzi(Y
} ?V#%^ 57p
} bK; -Xcm
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