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)); B Sb!{|]
} O_F<VV*MFQ
for(int i=0;i<nEndPos.length-1;i++) `Ph4!-6#
{ wAkoX
nEndPos = nStartPos[i+1]; TKRu^KH9
} w:MfaN*
nEndPos[nEndPos.length-1] = nFileLength; <ezvz..g
} 2!]':(8mR
} !WVF{L,/I
q3scz
pN*>A^
//启动子线程 %@H;6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4^AE;= Q
for(int i=0;i<nStartPos.length;i++) "=yaeEp
{ v,+2CVdW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2&$A x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qMI%=@=
nStartPos,nEndPos,i); J#:%| F%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qr<5z. %
fileSplitterFetch.start(); Bj%{PK
} %\r4c*O1q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1!vR 8.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (O&ooM* o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P}?,*'b
nEndPos = " + nFileLength); _4%+TN6z
// fileSplitterFetch[nPos.length-1].start(); V\ARe=IWM
8 A%)m
[Y'Xop6G
//等待子线程结束 ,a5I:V^\
//int count = 0; (U$ F) 7
//是否结束while循环 uERc\TZ
boolean breakWhile = false; ]dk~C?H
lW^RwNcd
S1&6P)X.Za
while(!bStop) dLQ!hKD~
{ $[FO(w@f
write_nPos(); hz\7Z+$L_
Utility.sleep(500); s|EP/=9i
breakWhile = true; EkOBI[`
~2rZL
?LvZEiJ
for(int i=0;i<nStartPos.length;i++) HK:?Y[ebs
{ T:na\y/{j
if(!fileSplitterFetch.bDownOver) f>p;Jh{2fn
{ =P0~=UP
breakWhile = false; bhuA,}
break; J,+| Fb
} G.T}^xHmL
} 0%'&s)#
if(breakWhile) ^(UL$cQ>
break; nW{7L
-] J V
3(AgUq
//count++; bX5>qqB]
//if(count>4) 1{nXmtvr
// siteStop(); Y}nE/bmx&9
} eCk}B$ 2
NsWyxcty
Ej6vGC.,
System.err.println("文件下载结束！"); ir%/9=^d
} x\x>_1oP
catch(Exception e){e.printStackTrace ();} Zroj-3-X~
} q|gG{9
[gH vI
=<a`G3SY!
//获得文件长度 W~dS8B=<
public long getFileSize() j6IWdqXe
{ Et`z7Q*e
int nFileLength = -1; }@a_x,O/x}
try{ #.FtPR
URL url = new URL(siteInfoBean.getSSiteURL()); f4`=yj*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hQ8/-#LO_
httpConnection.setRequestProperty("User-Agent","NetFox"); FS`{3d2K +
{T m-X`
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int responseCode=httpConnection.getResponseCode(); *Pw;;#\B
if(responseCode>=400) mm:\a-8j
{ !:rQ@PSy9
processErrorCode(responseCode); 8n);NZ
return -2; //-2 represent access is error IY,&/MCh
} *>S\i7RET
Td"f(&Hk&
oDM}h +
String sHeader; <P}{0Y~@*W
>RF[0s'-
$S=lm {
for(int i=1;;i++) [T~O%ly7x&
{ 2x3&o|J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p# O%<S@?
//Utility.log(in.readLine()); H4^-MSw
sHeader=httpConnection.getHeaderFieldKey(i); X^fMt]
if(sHeader!=null) }MXZ
{ yv4hH4Io
if(sHeader.equals("Content-Length")) ldi'@^
{ y=5s~7]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x1Z?x,-D"
break; wdl6dLu
} 7P=1+2V
} 2-]gHAw%
else 8cR4@Hqx
break; ^Zydy
} V0ulIKck
} ]rC6fNhQ
catch(IOException e){e.printStackTrace ();} q9icj
catch(Exception e){e.printStackTrace ();} '$q'Wl)
8Ay#6o
!Edc]rg7
Utility.log(nFileLength); pmIQD"
FeLWQn/aV6
9(ANhG
return nFileLength; _%z)Y=Q
} wgzjuTqwBF
jD$T
ryN/sjQC
//保存下载信息（文件指针位置） !u>29VN
private void write_nPos() 4TC !P}
{ 2+ >.Z.pX
try{ Yz\z Qj
output = new DataOutputStream(new FileOutputStream(tmpFile)); jJ|u!a
output.writeInt(nStartPos.length); kM]?
for(int i=0;i<nStartPos.length;i++) XvZg!<*OH
{ s26:(J [{
// output.writeLong(nPos); 9IC"p<D
output.writeLong(fileSplitterFetch.nStartPos); Hc5@gN
output.writeLong(fileSplitterFetch.nEndPos); h^?[:XBeav
} sAC1Pda
output.close(); @&mv4zz&W
} ) dwPD
catch(IOException e){e.printStackTrace ();} %HwPOEJ
catch(Exception e){e.printStackTrace ();} y%`^*E&
} 6hAeLlU1
r3_@ L>;
lNls8@
//读取保存的下载信息（文件指针位置） L?4c8!Q
private void read_nPos() nWmc
{ tjuW+5O
try{ mNWmp_c,1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @H1pPr
int nCount = input.readInt(); jYO@ %bQ
nStartPos = new long[nCount]; o @~XX@5l
nEndPos = new long[nCount]; $2 ~A^#"0
for(int i=0;i<nStartPos.length;i++) F+*: >@3
{ )Xl/|YD
nStartPos = input.readLong(); -Ufd+(
nEndPos = input.readLong(); t 0nGZ%`
} L8/o9N1
input.close(); 9I+;waLlB
} -:*PXu
catch(IOException e){e.printStackTrace ();} cC&R~h]|
catch(Exception e){e.printStackTrace ();} DZRkK3
} 9@:H9"w
=36vsps=
| z$ba:u5
private void processErrorCode(int nErrorCode) bX=ht^e[
{ eIg ' !8h?
System.err.println("Error Code : " + nErrorCode); )=[K$>0k
} %* vYX0W"
c^Rz?2x
3yZtyXRPn
//停止文件下载 (ZT*EFhb(
public void siteStop() ol:,02E&
{ s80:.B
bStop = true; \*v}IO>2})
for(int i=0;i<nStartPos.length;i++) S2;{)"mS
fileSplitterFetch.splitterStop(); q~_Nv5r%O
~}$:iyJV(>
J0C<Qb[
} D8paIp
} <!-8g!
//负责部分文件的抓取 ( y'i{:B
**FileSplitterFetch.java 4YXtl+G
*/ _ZC4O&fL
package NetFox; D0~WK stl
bhnm<RZ
m:/nw,
import java.io.*; It(8s)5
import java.net.*; :-Ho5DHg
J<>z}L{
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public class FileSplitterFetch extends Thread { *{)[:;
E)NH6~
/n/U)!tp
String sURL; //File URL W6E9
long nStartPos; //File Snippet Start Position f/eT4y
long nEndPos; //File Snippet End Position 0{gvd"q
int nThreadID; //Thread's ID v>~ottQ|
boolean bDownOver = false; //Downing is over lk2F]@_kJH
boolean bStop = false; //Stop identical vXq=f:y4
FileAccessI fileAccessI = null; //File Access interface ~pX&>v\T
i ao/l
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G5kM0vs6L
{ R^f~aLl
this.sURL = sURL; 9'Pyo`hJ#U
this.nStartPos = nStart; STVJu![
this.nEndPos = nEnd; J=Ak+J
nThreadID = id; B.'@~$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p%]*I?
} de[c3!#1d
4ME8NEE
C!Y|k.`p
public void run() xQk]a1
{ -]+XTsL
while(nStartPos < nEndPos && !bStop) +T"kx\<
{ 818</b<yn
.gG<08Z
gupB8 .!
try{ gTH1FR8$y
URL url = new URL(sURL); T9*\ITA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C ])Q#!D|
httpConnection.setRequestProperty("User-Agent","NetFox"); Ty*ec%U9F
String sProperty = "bytes="+nStartPos+"-"; 0u'4kF!P!
httpConnection.setRequestProperty("RANGE",sProperty); G|4vnIS
Utility.log(sProperty); y~SFlv36
O->i>d
Z?ZcQ[eC
InputStream input = httpConnection.getInputStream(); )>\J~{
//logResponseHead(httpConnection); &Sa<&2W4S
\Y Cj/tG8
wkdd&Nw;
byte[] b = new byte[1024]; F$ZWQ9&5U0
int nRead; PxfeU2^{0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lqF{Y<l
{ o~NeS|a
nStartPos += fileAccessI.write(b,0,nRead); l(v$+
//if(nThreadID == 1) l#\z3"b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KQJn\#>
} {l0;G)-
rPaD#GA[7
#E{aN?_
Utility.log("Thread " + nThreadID + " is over!"); 6mep|![6
bDownOver = true; h|!B;D
//nPos = fileAccessI.write (b,0,nRead); oeDsJ6;
} r{YyKSL1*K
catch(Exception e){e.printStackTrace ();} L`R,4mI.W
} CbQ@l@d]
} xv$^%(Ujp
>QE^KtZ
95T%n{rz
//打印回应的头信息 pnxjuDN7}x
public void logResponseHead(HttpURLConnection con) U`W^w%
{ >-s}1*^=oD
for(int i=1;;i++) dsR{ P,!
{ H'q&1^w)
String header=con.getHeaderFieldKey(i); $a15 8
if(header!=null) 6x]|IWvW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?uU0NKZA
Utility.log(header+" : "+con.getHeaderField(header)); \S=!la_T@m
else 9(ZzwkD'>
break; htX'bA
} 7v?tSob:b
} S82NU2L
hX`WVVoF
fX[,yc;
public void splitterStop() >, 234ab=d
{ )@]-bPnv
bStop = true; x3PeU_9
} ii2oWU
R>/M>*C
g"(N_sv?
} pcur6:8W!
a}i{b2B
'8*gJ7]
/* $#]?\psf
**FileAccess.java Qc[[@=S%
*//文件访问(定位，写) Yo| H`m,
package NetFox; IH\k_Yf#u
import java.io.*; iBp 71x65
P^rSpS9
L9Fx Lw41
public class FileAccessI implements Serializable{ .7ahz8v
u+I-!3J87
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z6Su`
RandomAccessFile oSavedFile; )6bxP&k
long nPos; Se0/ysVB
_N/]&|.. !
Xuh_bW&zF
public FileAccessI() throws IOException `3pe\s
{ B|:{.U@ne
this("",0); i$"FUC~'
} &\<RVE
:vurU$\
3C_g)5 _:
public FileAccessI(String sName,long nPos) throws IOException )@R:$l86
{ }^`{YD
oSavedFile = new RandomAccessFile(sName,"rw"); Gk[P-%%b /
this.nPos = nPos; 3-o ]H'6
oSavedFile.seek(nPos); (g7nMrE$j
} JGj_{|=:
<(BAws(X
YLSG 5vF+
public synchronized int write(byte[] b,int nStart,int nLen) 3qpkMu3
{ _JR4 PKtx
int n = -1; hZ2PP ^
try{ 7MoO2
oSavedFile.write(b,nStart,nLen); )&_{m K
n = nLen; ZmmuP/~2K
} Tw!x*
catch(IOException e) c}QQ8'_
{ ni~45WX3
e.printStackTrace (); oC4rL\d{
} (/k,q
GExG1n-
5Qy,Pkje
return n; f1=8I_>=
} uUc[s"\
-F8%U:2a
3g-}k
} tCc}}2bC&
;A-Ef
&v 5yo}s
/* ]nfS vPb
**SiteInfoBean.java ;H:qDBH
*/ c#HocwP@
package NetFox; 5~rs55W
$<ZX};/D
0HNe44oI+D
public class SiteInfoBean { fcw\`.
A=XM(2{aN
?[m5|ty#
private String sSiteURL; //Site's URL Llk`
private String sFilePath; //Saved File's Path HnY: gu
private String sFileName; //Saved File's Name 3_33@MM
private int nSplitter; //Count of Splited Downloading File jWU)y)$
?nt6vqaV
$mlsFBd
public SiteInfoBean() X='4N<
{//nSplitter的缺省值为5 57[O)5u.+
//default value of nSplitter is 5 JRodYXjE
this("","","",5); l
} 58v5Z$%--
u[dI81`
VKR6i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YO,GZD`-o
{ uk\GAm@O
sSiteURL= sURL; b%)a5H(
sFilePath = sPath; M2oKLRt)L
sFileName = sName; ait/|a
this.nSplitter = nSpiltter; QkF-}P%
eGguq~s`
'fVk1Qj^
} GGLVv)
~+T~}S
[xE\IqwM
public String getSSiteURL() x1Si&0T0P<
{ ]h|GaHiE
return sSiteURL; =3( ZUV X
} f3596a
a\%g_Q){
0e}LZ,9e
public void setSSiteURL(String value) kXOlZC
{ YEZ"BgUnbp
sSiteURL = value; +:Y6O'h.
} .d8~]@U!<
PMTyiwlm
UhEnW8^bz1
public String getSFilePath() wEkW=
{ kwyvd`J8
return sFilePath; ^T<<F}@q
} #K4wO!d
_Y~+ #Vc
.79'c%3}
public void setSFilePath(String value) }2h~o~
{ YE^|G,]
sFilePath = value; Ybok[5
} ;e[-t/SI
\,_%e[g49
=)T5Y,+rJ
public String getSFileName() rsc8lSjH
{ kj-Sd^
return sFileName; +Uk/Zg w^
} "urQUpF
tZ6KU11O
xUeLX`73
public void setSFileName(String value) F-ijGGL#
{ A!j&g(Z"Q
sFileName = value; (^6SF>'
} E8V,".!+E
w-\GrxlbX
J@)6]d/,
public int getNSplitter() QGYmQ9m{kL
{ Wm"W@LPx5
return nSplitter; :ox+WY
} aIm\tPbb
$MP'j9-S?
3N<FG.6
public void setNSplitter(int nCount) &1VC0"YJWy
{ >Vg<J~[g
nSplitter = nCount; N2x\O~7
} -ff*,b$Q/
} /O&j1g@
gN(8T_r
K\;b3
/* IJs`3?
**Utility.java M~wJe@bc
*/ o,X ?
package NetFox; Jj([O2Eq$
u/``*=Y@
fc&4e:Ve
public class Utility { g8B@M*JA
lJ}lO,g
;zp0,[r
public Utility() !qy/'v4
{ )WBTqML[
C9*'.~
VV?KJz=,W=
} #Ok*Or
*xt3mv/<z
//线程睡眠 OHH wcJ7N
public static void sleep(int nSecond) :GO}G`jY
{ ^OYar(
try{ \f%jN1z
Thread.sleep(nSecond); eyUo67'7
} IF@)L>-%
catch(Exception e) Rb\\6BU0
{ :,:r
e.printStackTrace (); ` NcWy
} #:236^xYS
} sH#UM(N
$0{c=r9
//日志 iGm[fxQ|
public static void log(String sMsg) L%N|8P[
{ NbfV6$jo
System.err.println(sMsg); -4"E]f
} Oi=kL{DG:s
VBsS1!g
LL.YkYu
public static void log(int sMsg) q(_pk&/
{ 4WDh8U
System.err.println(sMsg); nV GrW#'E
} /1g_Uv;
} ,LU/xI0O
RXLD5$s^
CYs:P8^
/* MSsboSxA
**TestMethod.java rT5dv3^MW!
*/ >*dqFZF
package NetFox; t|d9EC]c(
@ Al\:
hesL$Z [
public class TestMethod { e=TB/W_
b6Dve]
kW5g]Q
public TestMethod() =A04E
{ ///xx/weblogic60b2_win.exe tecCU[O
try{ (|"KsGl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PJS\> N&u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;#cb%e3
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZB<goEg
fileFetch.start(); t-i;
} KR%DpQ&{'
catch(Exception e){e.printStackTrace ();} )"wWV{k
-+-@Yq$
^6oz3+
} Mb uD8B
XeKIue@_
HTvA]-AuM
public static void main(String[] args) 8(7DW |\
{ ytKh[Uo
new TestMethod(); U"af3c^2
} 9JpPas$]
} q:+,'&<D
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