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#0R
} }Jt( H
for(int i=0;i<nEndPos.length-1;i++) r@+IDW.=9
{ c_xtwdkL9
nEndPos = nStartPos[i+1]; iK%<0m
} R}4o{l6
nEndPos[nEndPos.length-1] = nFileLength; SymSAq0$F
} X ^>o/U
} uf,4GPo,
S1^u/$*6
*zX*k7LnV
//启动子线程 =tl[?6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NUBzmnA>8
for(int i=0;i<nStartPos.length;i++) N1WP
{ Ky`rf}cI>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U:>'^tkp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C,C%1
nStartPos,nEndPos,i); ByeyUw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J=67As
fileSplitterFetch.start(); J) v~
} ''!pvxA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O!='U!X@P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZC3b9:tk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 13Ga #
nEndPos = " + nFileLength); O z%K*
// fileSplitterFetch[nPos.length-1].start(); ~u1ox_v`%(
!c:Q+:,H
1Nx.aji
//等待子线程结束 :7p0JGd
//int count = 0; evPr~_
//是否结束while循环 2}]6~i
boolean breakWhile = false; zvL&V .>
{ yU1db^
)F&@ M;2p'
while(!bStop) H[V^wyi'z
{ wXDF7tJh
write_nPos(); 4cL NPl<
Utility.sleep(500); -h*Yd)
breakWhile = true; &/R@cS6}'
)gV+BHK
(w]w 2&YD
for(int i=0;i<nStartPos.length;i++) aGNVqS%y
{ JU:!lyd
if(!fileSplitterFetch.bDownOver) %Rr!I:[ $
{ 5/DTE:M<
breakWhile = false; wRb%-s
break; y?<[g;MuT
} RGhl`;
} v83uGEq(
if(breakWhile) Vj4 if@Z
break; c a_N76o!
F}0QocD
Rp A76ug
//count++; E xKH%I
//if(count>4) KoiU\r
// siteStop(); Ql%7wrK
} =nFT0];
B+);y
*x`z5_yfO
System.err.println("文件下载结束！"); x`PIJE
} K%qunjv
catch(Exception e){e.printStackTrace ();} W)^:*z
} 52m^jT Sx
>?'q P ]
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//获得文件长度 vPmP<c)cb
public long getFileSize() "+_]N9%)
{ %%c0UaV
int nFileLength = -1; (&PamsV*8
try{ ,p1 (0i
URL url = new URL(siteInfoBean.getSSiteURL()); rZu_"bcJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >1pD'UZIy7
httpConnection.setRequestProperty("User-Agent","NetFox"); @M#2T
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int responseCode=httpConnection.getResponseCode(); {,IWjt &>
if(responseCode>=400) "c!s\iuBU
{ ||`w MWq
processErrorCode(responseCode); }S*6+4
return -2; //-2 represent access is error T 6QnCmB4
} lx$Y-Tb^F
IS&`O=7
HZ8 j[kO
String sHeader; C$*`c6R
cD0
IL.Jx:(0
for(int i=1;;i++) ~pzaX8!
{ cnLC>_hY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 32~Tf,
//Utility.log(in.readLine()); 1Dt"Rcn"4
sHeader=httpConnection.getHeaderFieldKey(i); -mY90]g
if(sHeader!=null) $nn~K
{ <g*rTqT'
if(sHeader.equals("Content-Length")) M|n)LyL
{ %M}zi'qQ?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rFx2S
break; dZ%b|CUb
} q{U -kuui
} Maa5a
else ~;+i[Z&e
break; *}/xy SH3
} &51/Pm2O
} I,YGm
catch(IOException e){e.printStackTrace ();} "b1_vA]03
catch(Exception e){e.printStackTrace ();} I.KYWs
v/m`rc]e
v~jN,f*
Utility.log(nFileLength); ~%<PEl|
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GC4$9q}C4Z
return nFileLength; JYSw!!eC
} FblGFm"P
:[ITjkhde0
rA1 gH6D
//保存下载信息（文件指针位置） }rO4b>J
private void write_nPos() MO _9Yi
{ 7PQedZ<\
try{ @=;6:akz`
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2Cr+Z(f
output.writeInt(nStartPos.length); W!X#:UM)
for(int i=0;i<nStartPos.length;i++) fx;5j;
{ r#Pd@SV
// output.writeLong(nPos); 8U;!1!+ 7)
output.writeLong(fileSplitterFetch.nStartPos); z? {#/
output.writeLong(fileSplitterFetch.nEndPos); z9D2,N.
} (XW#,=rYk
output.close(); Fn[~5/
} qb"!
catch(IOException e){e.printStackTrace ();} QlXy9-oJ"
catch(Exception e){e.printStackTrace ();} Rp@u.C<
} htF&VeIte
(vI7qD_
R(zsn;
//读取保存的下载信息（文件指针位置） wz, \zh
private void read_nPos() \]9;c6(
{ #5H@/o8!s=
try{ KDXo9FzF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Iewq?s\Fo
int nCount = input.readInt(); wZC'BLD
nStartPos = new long[nCount]; ~f@<]
nEndPos = new long[nCount]; &>s(f-\8
for(int i=0;i<nStartPos.length;i++) +$UfP(XmH
{ iF%q6R
nStartPos = input.readLong(); SHGO;
nEndPos = input.readLong(); Fx@ {]
} B}MJ?uvA
input.close(); sRMzU
} `Ch6"=t
catch(IOException e){e.printStackTrace ();} P\M+ZA ;
catch(Exception e){e.printStackTrace ();} 8odVdivh
} HhpP}9P;
$(NfHIX
~Fx[YPO,
private void processErrorCode(int nErrorCode) q6ikJ8E8b
{ "~[Rwh?
System.err.println("Error Code : " + nErrorCode); - a=yid
} t]` 2f3UO
q@\_q!
.Yf h*
//停止文件下载 .U1dcL6
public void siteStop() fC-^[Af)
{ p;5WLAF
bStop = true; b9YpUm7#
for(int i=0;i<nStartPos.length;i++) D3K`b4YV
fileSplitterFetch.splitterStop(); 6 %=BYDF
JxvwquI
tS9m8(Hr%Q
} 1y@-
} H,I}R
//负责部分文件的抓取 :D,YR(])
**FileSplitterFetch.java -?]ltn9!
*/ lvN{R{7>
package NetFox; W+eN%w5
;+jp,( 7
oF>GWstTR
import java.io.*; E??%)q
import java.net.*; C=]3NB>Jc
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#<~f~{x
public class FileSplitterFetch extends Thread { F9<OKcXH
Cn55%:
[x)e6p)
String sURL; //File URL yjr@v!o
long nStartPos; //File Snippet Start Position m3WV<Cbz
long nEndPos; //File Snippet End Position w\mF2h
int nThreadID; //Thread's ID N<{`n;
boolean bDownOver = false; //Downing is over BmM,vllO
boolean bStop = false; //Stop identical esHiWHAC
FileAccessI fileAccessI = null; //File Access interface xL BG}C
|")x1'M
`u}x:f !
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #.><A8J
{ $W?XxgkB?
this.sURL = sURL; nx4aGS"F:
this.nStartPos = nStart; \fhT#/0N
this.nEndPos = nEnd; S?{5DxilO
nThreadID = id; ,YY#ed&l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '-vyQ^
} 4 * OU
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public void run() Z~uKT n
{ br;G5^j3?
while(nStartPos < nEndPos && !bStop) 42u\Y_^ID
{ md`ToU
aYgJTep>r
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try{ wgyO%
URL url = new URL(sURL); hG@ys5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `[KhG)Y7t
httpConnection.setRequestProperty("User-Agent","NetFox"); LnDj
String sProperty = "bytes="+nStartPos+"-"; QdTe!f|
httpConnection.setRequestProperty("RANGE",sProperty); AH`15k_i
Utility.log(sProperty); 1+jYpYEQW
rTm{-b)r
["F,|e{y$
InputStream input = httpConnection.getInputStream(); 9yh@_~rZ
//logResponseHead(httpConnection); zFn&~lFB
.ndQ(B
LC{hoq\
byte[] b = new byte[1024]; T]W -g
int nRead; 8x"d/D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f*],j
{ (HI%C@e9
nStartPos += fileAccessI.write(b,0,nRead); gp HwiFc
//if(nThreadID == 1) 9qDGxW '1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dkb&/k:)
} 2FzS_\":I
RV`j>1
{H V,2-z
Utility.log("Thread " + nThreadID + " is over!"); RuZ;hnE&
bDownOver = true; ='0!B]<G
//nPos = fileAccessI.write (b,0,nRead); m'tk#C
} ?nW#qy!R
catch(Exception e){e.printStackTrace ();} dmz3O(]$
} YZl%JX
} ,7P^]V1
!P$xh
\2pFFVT
//打印回应的头信息 A232"p_
public void logResponseHead(HttpURLConnection con) E5 oD|'=WA
{ Y2-bU 7mo
for(int i=1;;i++) >n~p1:$
{ HIm, "iYk
String header=con.getHeaderFieldKey(i); 1RbYPX
if(header!=null) $0}bi:7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BA-nxR
Utility.log(header+" : "+con.getHeaderField(header)); qJU)d
else )|R9mW=k9P
break; =-LX)|x}
} gi'agB^
} ^4pKsO3ul
W_\L_)^X
3|Sy'J0'K
public void splitterStop() Ki/5xK=s
{ cl{W]4*$
bStop = true; V1)P=?%(US
} i8_x1=A
*\KvcRMGUa
SRN9(LN
} qLi9ym, ]
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!9xANSb
/* /}`/i(k
**FileAccess.java |.O!zRm
*//文件访问(定位，写) `l2<
package NetFox; d[e:}1
import java.io.*; z-G7Y#
IXvz&4VD
&17,]#3
public class FileAccessI implements Serializable{ ef}E.Bl
|sqo+E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @gSFvb bc
RandomAccessFile oSavedFile; 8@yc}~8 *
long nPos; U@J/
iW1ih QX
N~; khS]
public FileAccessI() throws IOException {L4>2rF
{ o1X/<.0+
this("",0); x*&&?nV Iz
} 6!%d-Z7)
x)VIA]
m>+,^`0
public FileAccessI(String sName,long nPos) throws IOException i\Pr3 7 "
{ 9MB\z"b?A
oSavedFile = new RandomAccessFile(sName,"rw"); ?[S >&Vq
this.nPos = nPos; frmqBCVJ:
oSavedFile.seek(nPos); W]D`f8r9
} 52MCUl
>[XOMKgQ](
-[=AlqL
public synchronized int write(byte[] b,int nStart,int nLen) a\&(Ua
{ 1R2o6`_
int n = -1; #OD@q;
try{ o7Cnyy#:
oSavedFile.write(b,nStart,nLen); ~*mOt7G
n = nLen; k>:/D
} p&OJa$N$[
catch(IOException e) (I7&8$Zl
{ JMirz~%ib
e.printStackTrace (); 1akD]Z
} Q.9Ph ~
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68p\WheCal
return n; 5mna7BCEb
} h\=p=M
JA?,0S
Siz!/O!'
} ZSF=
m~Y'$3w
HzD>-f
/* t,=@hs hN
**SiteInfoBean.java FVsu8z u
*/ >9o,S3
package NetFox; +}c|O+6g
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6(N.T+;]
public class SiteInfoBean { + ZR(
A*7Io4e!
lFp!XZ!
private String sSiteURL; //Site's URL M^j<J0(O
private String sFilePath; //Saved File's Path O+G~Qp0b>
private String sFileName; //Saved File's Name e9~cBG|
private int nSplitter; //Count of Splited Downloading File Y!++CMzU
0|+>A?E}E
|8&-66pX
public SiteInfoBean() j+_S$T8w
{//nSplitter的缺省值为5 I@3Q=14k%
//default value of nSplitter is 5 o &BPG@n
this("","","",5); 8- dRdQu]
} *Rz{44LP&
TK;\_yN
k~0#'I9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) abM84EU
{ :D"@6PC]
sSiteURL= sURL; La`h$=#`
sFilePath = sPath; 3C277nx
sFileName = sName; 5a=nF9/
this.nSplitter = nSpiltter; a`7%A H)
uew0R;+oa
Y3-]+y%l
} >?S\~Y
=y?#^
'n~fR]h}
public String getSSiteURL() %lXbCE:[
{ 3H1Pp*PH
return sSiteURL; (l Lu?NpIi
} ,/~[S
N g58/}zO
?K0U3V$s
public void setSSiteURL(String value) -Bj.hx*
{ 6H0W`S0a
sSiteURL = value; 3f_i1|>)'
} ]x1p!TSU
>Cvjs
aIQOs
public String getSFilePath() G]b8]3^
{ i#k-)N _$
return sFilePath; -<6v:Z
} iu+3,]7Fm
:JR<SFjm
F@9Y\. ,
public void setSFilePath(String value) d5Qd'
{ -)X{n?i
sFilePath = value; s,w YlVYf!
} [KMS<4t'
w}d}hI
f7Zf}1|
public String getSFileName() WJAYM2 6\
{ :.DI_XN`
return sFileName; QskUdzQ=
} L%f;J/
t~ -J %$
0rcjorWI
public void setSFileName(String value) mk\i}U>`
{ A';n6ne%i
sFileName = value; wk@yTTnb
} dQai4e>[
Yc d3QRB
YxJ`-6
public int getNSplitter() v`SY6;<2
{ %]#VdS|N
return nSplitter; l&3ki!
} z>|)ieL
Y#`Lcg+r,
YN^T$,*
public void setNSplitter(int nCount) :c=v}
{ -AC`q/bCD
nSplitter = nCount; 6|^0_6_
} SW#BZ3L
} T/5"}P`
lBmm(<~Z
Ft) lp>3gv
/* U@?6*,b(.
**Utility.java YDFCGA
*/ 69/?7r
package NetFox; `L\)ahM
.LObOR5J7
72,"Cj
public class Utility { x'qWM/
13a(FG
q^*6C[G B
public Utility() ej52AK7
{ wbi3lH:;
9U^$.Lb
Us-A+)r*!
} ] H&c'
kaQ2A
//线程睡眠 P'tMu6+)
public static void sleep(int nSecond) ^i'y6J
{ LeHiT>aX!
try{ /.$L"u
Thread.sleep(nSecond); :6lwO%=F
} M4?8xuC
catch(Exception e) %!y89x=E
{ =IHje;s
e.printStackTrace (); q8sbn
} w!`Umll2
} hS:jBp,
XlkGjjW#/J
//日志 ArzDI{1
public static void log(String sMsg) 2\0Oji\6
{ [se^.[0,
System.err.println(sMsg); c!Dc8=nE0m
} z(H?VfJo
|pW\Ec#(
6Cc7ejt|u
public static void log(int sMsg) JE!("]&
{ -(IC~
System.err.println(sMsg); V=}1[^
} |0 !I5|<k
} i-lKdpv
I:$"E% >=
IU!Ht>
/* 4:1)~z
**TestMethod.java ]V<-J
*/ wsnK3tM7-
package NetFox; mqFq_UX/T
|J3NR`-R
AhxGj+
public class TestMethod { n?E}b$6
k^An97J
uZ(? >
public TestMethod() `.^ |]|u
{ ///xx/weblogic60b2_win.exe P5?<_x0v4b
try{ `ZGcgO<c\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8eyl,W=dn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ({[,$dEa;
SiteFileFetch fileFetch = new SiteFileFetch(bean); wss?|XCI
fileFetch.start(); ]b}B2F'n
} YV([2
catch(Exception e){e.printStackTrace ();} $1@,Qor
*H2]H@QHN
N 8t=@~]
} (E!!pz
kso*}uh0
S>f&6ZDNY(
public static void main(String[] args) ]J@/p:S>
{ 36$[
new TestMethod(); Vb)zZ^va+
} `|Fp^gM
} 'HaD~pa
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