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)); 0=N4O!X9
} 3gxf~$)?
for(int i=0;i<nEndPos.length-1;i++) ~hS .\h
{ K:}h\ In
nEndPos = nStartPos[i+1]; (A7T}znG
} M*g2VyZ
nEndPos[nEndPos.length-1] = nFileLength; $x;tSJ)m~
} i:l80 GK
} httls>:xB|
C!$Xv&"r
S[-.tvI;Q
//启动子线程 QT`fix{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pu\b`3C(
for(int i=0;i<nStartPos.length;i++) 68vxI|EZ
{ ?~F]@2)5w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 06PhrPVa!\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?,WUJH?^
nStartPos,nEndPos,i); DWF >b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ::p-9F
fileSplitterFetch.start(); iP~sft6
} ,DE(5iDS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'bLP~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Eem 2qKj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ix( 6
nEndPos = " + nFileLength); ,$HHaoog
// fileSplitterFetch[nPos.length-1].start(); ,3G$`
UqD5 A~w
fdd~e52f
//等待子线程结束 PLO\L W
//int count = 0; "F&Tnhh4
//是否结束while循环 b cC\
boolean breakWhile = false; l9]o\JFXk
|C~Sr#6)7
l)}<#Ri
while(!bStop) b2a'KczV
{ 9U!JK3d
write_nPos(); +ckMT3
Utility.sleep(500); slu$2-H
breakWhile = true; r`?&m3IOP
0w^jls
I|$'Q$m~
for(int i=0;i<nStartPos.length;i++) V%i<;C
{ ZkwJ.SuU
if(!fileSplitterFetch.bDownOver) PqTYAN&F
{ b OW}"
breakWhile = false; uEBQoP2
break; Xyb8u})p'
} {\P?/U6~f
} q A.+U:I8
if(breakWhile) G"}qV%"6"
break; )$MS 0[?
[Dnusp7e
RI?NB6U
//count++; ;_x2Ymw
//if(count>4) C#Y,r)l
// siteStop(); 4DvdEt
} .8-PB*vb
G?>qd}]y0L
K3Huu!Tr
System.err.println("文件下载结束！"); 2q+la|1Cr
} DKR<W.!*t
catch(Exception e){e.printStackTrace ();} OdO{xG G@
} 4"LPJX)Q
baqn7k"
N[>:@h
//获得文件长度 3QH(4N
public long getFileSize() _\p`4-.V
{ n1_ %Td
int nFileLength = -1; @v"T~6M
try{ STv(kQs
URL url = new URL(siteInfoBean.getSSiteURL()); TV<Aj"xw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pH^ z
httpConnection.setRequestProperty("User-Agent","NetFox"); b7Yq_%+
L%f-L.9`u
5Qb;2!
int responseCode=httpConnection.getResponseCode(); %?@x]B9Y8E
if(responseCode>=400) =1O?jrl~q
{ AD(xaQ&T
processErrorCode(responseCode); e,^pMg~
return -2; //-2 represent access is error }Bd_:#.mw
} 6{L F-`S%
V!mWn|lf
"@(58nk
String sHeader; OO$|9`a
OthG7+eF
61G|?Aax
for(int i=1;;i++) -H4PRCDH
{ {d8^@UL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k@7kNMl
//Utility.log(in.readLine()); !!9{U%s
sHeader=httpConnection.getHeaderFieldKey(i); u]R$]&<
if(sHeader!=null) U8E0~[y'
{ #0(fOHPQ
if(sHeader.equals("Content-Length")) %t q&
{ [ ynuj3G V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >)4.$#H
break; )4PB<[u
} |%-YuD
} Rb?~ Rs\
else li@kLh
break; Urn
} t~q?lT
} )TM!ms+K
catch(IOException e){e.printStackTrace ();} M'YJ"
catch(Exception e){e.printStackTrace ();} I`3d;l;d
_n7%df
h:_NA
Utility.log(nFileLength); ~bWhth2*
JXL'\De ;
)t5;d
return nFileLength; >n(F4C-pl
} s~=g*99H
CNq[4T'~A
f7ZA837Un
//保存下载信息（文件指针位置） ZH!;z-R
private void write_nPos() H)\4=^
{ whw{dfE
try{ v3~FR,Kl
output = new DataOutputStream(new FileOutputStream(tmpFile)); \PzN XQ$
output.writeInt(nStartPos.length); NfOp=X?Y
for(int i=0;i<nStartPos.length;i++) [Q|M/|mnR1
{ 9Kx<\)-GMD
// output.writeLong(nPos); 5 1"8Py
output.writeLong(fileSplitterFetch.nStartPos); E3bwyK!s
output.writeLong(fileSplitterFetch.nEndPos); ?H<~ac2e
} \d:h$
output.close(); loLKm]yV
} }Iip+URG
catch(IOException e){e.printStackTrace ();} uQWp+}>ZJy
catch(Exception e){e.printStackTrace ();} 4AuH1m)<
} Ep<YCSQy$i
RU7!U mf
9?$RO[vo
//读取保存的下载信息（文件指针位置） x`#22"m
private void read_nPos() ;c$@@l
{ 4? v,wq
try{ ,!hnm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \x(.d.l/
int nCount = input.readInt(); UP?D@ogl<
nStartPos = new long[nCount]; ;HP#bx
nEndPos = new long[nCount]; 2p+C%"n>
for(int i=0;i<nStartPos.length;i++) ^B|YO8.v
{ -nOq\RYV
nStartPos = input.readLong(); ] ;&"1A
nEndPos = input.readLong(); ZOC#i i`:
} >GmN~"iJ
input.close(); QTfu:m{
} &/iFnYVhy
catch(IOException e){e.printStackTrace ();} >2u y
catch(Exception e){e.printStackTrace ();} g9`[Y~
} YQ+^
-( (Z@T1k
lYP~3wp99
private void processErrorCode(int nErrorCode) s+'XQs^{aj
{ UTvs |[
System.err.println("Error Code : " + nErrorCode); !D7"=G}HD
} BD4`eiu"
#%4=)M>^
&lq^dFP&Su
//停止文件下载 gd_^
public void siteStop() p0Z:Wkz]
{ 8!;$qVt
bStop = true; |UYED%dC
for(int i=0;i<nStartPos.length;i++) Ox~ 9_d
fileSplitterFetch.splitterStop(); l0. FiO@_Q
bb}?h]a
4QO/ff[ o
} $e*B:}x}
} 9{$8\E9*nd
//负责部分文件的抓取 (uRZxX
**FileSplitterFetch.java Fh^ox"3c
*/ :pb67Al29
package NetFox; ;$z7[+M
3T?f5+@I
'u1=XX h
import java.io.*; +v!v[qn
import java.net.*; Hsgy'X%om
KxX[S.C
!VFem~'d
public class FileSplitterFetch extends Thread { R5gado
6< >SHw
*%I[ ke *
String sURL; //File URL 4~Dax)
long nStartPos; //File Snippet Start Position `zY!`G
long nEndPos; //File Snippet End Position DRp&IP<
int nThreadID; //Thread's ID F3Ap1-%z
boolean bDownOver = false; //Downing is over yjFe'
boolean bStop = false; //Stop identical r^Y~mq
FileAccessI fileAccessI = null; //File Access interface F3Dt7q
ol<lCp
A4 5m)wQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Mc:bU
{ 3p&jLFphL
this.sURL = sURL; 7 v~ro
this.nStartPos = nStart; ~#q;bS
this.nEndPos = nEnd; ;:T9IL
nThreadID = id; .&PzkqWZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Je@kiE
} kN.B/itvA
^SAq^3^P!
gApz:K[l
public void run() _YLUS$Zw
{ 'bPk'pj9
while(nStartPos < nEndPos && !bStop) r@yD8D \
{ ami09JHy
Dkw*Je#6PX
ED/FlL{
try{ y1#O%=g
URL url = new URL(sURL); \lW_f{X)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r:NH6tAL
httpConnection.setRequestProperty("User-Agent","NetFox"); &XtRLtgS
String sProperty = "bytes="+nStartPos+"-"; {_(+>v"eJ
httpConnection.setRequestProperty("RANGE",sProperty); Zih ?Bm
Utility.log(sProperty); lV)G@l[1
NpR6
cQn)^jx=
InputStream input = httpConnection.getInputStream(); [@|be.g
//logResponseHead(httpConnection); {xToz]YA
Ye@t_,)x
$_FZn'Db6
byte[] b = new byte[1024]; rVcBl4&1*g
int nRead; np=kTJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `iQqhx
{ \K}aQKB/j
nStartPos += fileAccessI.write(b,0,nRead); 8YKQItK
//if(nThreadID == 1) o:9$UV[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B2(,~^39
} 3S;N(A4
cix36MR_
"{ FoA3g|
Utility.log("Thread " + nThreadID + " is over!"); ($SLb6
bDownOver = true; auL^%M|$R
//nPos = fileAccessI.write (b,0,nRead); |Euus5[
} K:_($X]
catch(Exception e){e.printStackTrace ();} 0+j}};
} [e1L{_*l
} *KJ7nRKx(w
Nxi)Q$
ESv:1o`?n
//打印回应的头信息 L/fRF"V
public void logResponseHead(HttpURLConnection con) VaJfD1zd1
{ Onw24&
for(int i=1;;i++) az2Xch]
{ 0m&3?"5u
String header=con.getHeaderFieldKey(i); ,E9d\+j
if(header!=null) NnOI:X {
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gc,Ps
Utility.log(header+" : "+con.getHeaderField(header)); 8^vArS;
else P#*n3&Uu
break; !.-.#<<_a
} )8'jxiGs
} 4|f}F
`)tA YH
PUCx]5
public void splitterStop() ~K`1
{ bjzx!OCpV
bStop = true; Ow)R|/e/
} R&Ci/
no|Gq>Xp
TY6 rwU
} +NR n0 z(
jyQVSQs
K(OaW)j
/* Y 1y E
**FileAccess.java K'Spbn!nC
*//文件访问(定位，写) v20~^gKo=m
package NetFox; SH=:p^J
import java.io.*; =~JfVozU
JO}?.4B
tT-=hDw
public class FileAccessI implements Serializable{ 9|3o<
oIxH3T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hVf^
RandomAccessFile oSavedFile; ERC<Dd0
long nPos; lwJipIO
vi|Zit
|_nC6;
public FileAccessI() throws IOException +nQ!4
{ <T4(H[9B
this("",0); a.,i.2
} ?0z)EPQ|
f[}|rf
<\ETPL,<
public FileAccessI(String sName,long nPos) throws IOException 1Z 6SI>p
{ !g2a|g
oSavedFile = new RandomAccessFile(sName,"rw"); r0Z+RB^I
this.nPos = nPos; =YHt9fb$c
oSavedFile.seek(nPos); j ug'g
} j+Zt.KXjT
#_fY4vEO
?gG,t4D
public synchronized int write(byte[] b,int nStart,int nLen) MD4\QNUa)*
{ ^@"c`
int n = -1; k>>`fE\K
try{ \ 3G*j`
oSavedFile.write(b,nStart,nLen); &k+*3.X
n = nLen; ev"M;"y
} r=$gT@
catch(IOException e) WIG=D{\Yx
{ Tq#<Po $
e.printStackTrace (); -l JYr/MSL
} xFwXW)
27iy4(4
_+n;A46
return n; c'rd$
} kwF]TO S
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b0YNac.l
} \u8,!) 4i
ttj2b$M,
`:4MMr91
/* 50,Y
**SiteInfoBean.java O9*p0%ug
*/ `p1DaV
package NetFox; S+pP!YX
\xeVDKJH+n
k/bque
public class SiteInfoBean { 6w!e?B2/%
L=m:/qQL
"l2bx
private String sSiteURL; //Site's URL ]#5^&w)'
private String sFilePath; //Saved File's Path 5[<F_"x
private String sFileName; //Saved File's Name OpqNEo\
private int nSplitter; //Count of Splited Downloading File GA ik;R
8f-:d]
;dOs0/UM&
public SiteInfoBean() Mciq-c)
{//nSplitter的缺省值为5 Y}/c N\
//default value of nSplitter is 5 |z+9km7,
this("","","",5); kO+s+ 55
} %YCd%lAe,
VF=Z`
<`+zvUx^?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f?0D%pxc}&
{ 17i$8
sSiteURL= sURL; /x/4NeD
sFilePath = sPath; ((cb4IX
sFileName = sName; 6Hn)pD#U
this.nSplitter = nSpiltter; m#MlH=-
agW9Go_F[
_uJVuCc
} >HIt}Zh
r`[B@
0\wiam-
public String getSSiteURL() BkV(81"C
{ jN{Zw*
return sSiteURL; 0d`5Gy_D%
} M8zE3;5
w%rg\E
j8c6[ih
public void setSSiteURL(String value) 3I\m,Ob
{ [?I/Uo8
sSiteURL = value; 3G.r-
} B0"0_n7-
0T0/fg(o
_25d%Ne0
public String getSFilePath() pI5_Hg
{ hb<k]-'!
return sFilePath; Pxk0(oBX
} *`1bc'umM;
9t}J|09i
A!4VjE>
public void setSFilePath(String value) 5A,=vE
{ 3`ml; L?D
sFilePath = value; j[H0SBKC
} Ge0Lb+<G
=1/q)b,p)
zv@bI~3~
public String getSFileName() U3N(cFXn
{ Th/{x h
return sFileName; /ISLVp%H
} Q ]0r:i= .
Oa1'oYIHg
eK*W=c#@
public void setSFileName(String value) kXMP=j8
{ >fg4x+0%
sFileName = value; NhCAv+
} s,kU*kHn
}\VX^{K j
cafsMgrA
public int getNSplitter() }U i_ynZ!
{ W6M jQ%f
return nSplitter; vs\|rLa
} jOv~!7T
H@4/#V|Uy
[n!x&f8Xh
public void setNSplitter(int nCount) m\?\6Wk
{ E9L!)D]Y
nSplitter = nCount; 4]IKh,jT
} k{1b20
} EP(Eq
CdNih8uG
^6#-yDZC@
/* . wmkj
**Utility.java jNIUsM8e
*/ j6}$+!E
package NetFox; ~M; gM]r;
s{B_N/^
Wxc^_iqA1
public class Utility { h&P {p _Y
d "B5==0I
La]4/=a
public Utility() z 7@ 'CJ
{ q}e]*]dJZ
+xq=<jy
9GE]<v,_[
} d9|T=R
ve~C`2=;
//线程睡眠 8lpzSJP4k
public static void sleep(int nSecond) 0H<4+ *`K
{ Z7oaQ\fR
try{ @f%wd2
Thread.sleep(nSecond); )lOji7&e
} =nw0# '
catch(Exception e) u X>PefR
{ Q~b_dx{m
e.printStackTrace (); boIVU`F-!
} d _uFY:
} g*28L[Q~
}`#Bf
//日志 BPqwDjW
public static void log(String sMsg) YY\Rua/nG
{ I0(8Z]x
System.err.println(sMsg); a 1NCVZ
} C?S~L5a#oC
tbY SK
=:;YTie
public static void log(int sMsg) RpjSTV8Tkm
{ pb6 Q?QG,
System.err.println(sMsg); Z+Xc1W^
} OK.-]()!
} }d@LSaM
T6;>O`B.r
P$Axc/H
/* FJW`$5?
**TestMethod.java -h=c=P
*/ ?f9$OLEB
package NetFox; s 8Jj6V
y6bjJ}
Ty.drM
public class TestMethod { }\U0[x#q
5qeT4| Ol
A xRl*B
public TestMethod() ]yw_n^@
{ ///xx/weblogic60b2_win.exe 2}597Hb
try{ =[APMig,n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FW/)uf3I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A<a2TXcIE3
SiteFileFetch fileFetch = new SiteFileFetch(bean); t ]71
fileFetch.start(); NavOSlC+h
} < rv1IJ
catch(Exception e){e.printStackTrace ();} j\nE8WH
Pb*q;9
s8{-c^G:R
} UP5%C;
^GrNfB[Qu
xu`d`!Tx
public static void main(String[] args) Vvxa.B
{ 'T6B_9GQ8
new TestMethod(); Feh"!k <6k
} kqQphKkL
} B#;s(O
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