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)); NL0n009"c$
} QS]1daMIK<
for(int i=0;i<nEndPos.length-1;i++) }<y7bqA
{ @[i4^
nEndPos = nStartPos[i+1]; om-omo&,X=
} Q({ r@*g
nEndPos[nEndPos.length-1] = nFileLength; m<qJcZk
} +V^;.P</
} [bNx^VP*
\`\ZTZni
h@]XBv
//启动子线程 Wh2tNyS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h@WhNk7"xa
for(int i=0;i<nStartPos.length;i++) Ziu]'#
{ 2oRg 2R}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A4<Uu~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8d-t|HkN
nStartPos,nEndPos,i); ;K&o-y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JNUt$h
fileSplitterFetch.start(); B=A [ymm
} pDCeQ6?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3+fp2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9lH?-~9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U,-39mr
nEndPos = " + nFileLength); cFnDmtI:
// fileSplitterFetch[nPos.length-1].start(); l.bYE/F0&
jc f #6
#!KE\OI;@5
//等待子线程结束 YgV817OV
//int count = 0; zXxT%ZcCj
//是否结束while循环 4l45N6"
boolean breakWhile = false; 6Yxh9*N~]
YLE!m?
'9j="R;
while(!bStop) mh[75(
{ Gc;{\VU
write_nPos(); 6N S201o
Utility.sleep(500); O[)kboY
breakWhile = true; K]"#C
[ )dXIIM
JU5C}%Q6
for(int i=0;i<nStartPos.length;i++) b4ONh%
{ A_5P/ARmI
if(!fileSplitterFetch.bDownOver) 0h\smqm
{ -Z Ugx$
breakWhile = false; CxG#"{&
break; vucxt }Ti
} Om@C X<(9C
} :GP]P^M;G@
if(breakWhile) ApV~(k)W
break; ~C`^6UQr/?
9g"2^^wD
wN-d'-z/rd
//count++; {I#]@,
//if(count>4) 1@1U/ss1
// siteStop(); c%G{#}^2
} #(JNn'fzq
<\ :Yk
c~uKsU
System.err.println("文件下载结束！"); tL)t" i
} >X4u]>X
catch(Exception e){e.printStackTrace ();} Zk"eA'"\
} k$J zH$
kB|B
~h85BF5
//获得文件长度 &NoS=(s,
public long getFileSize() VAf1" )pC
{ 9Ujo/3,Ak
int nFileLength = -1; z'\_jaj^
try{ E!l!OtFL
URL url = new URL(siteInfoBean.getSSiteURL()); SY^t} A7:/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b+6\JE^Mz
httpConnection.setRequestProperty("User-Agent","NetFox"); Xudg2t)+K
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int responseCode=httpConnection.getResponseCode(); )~] (&
if(responseCode>=400) NzOo0tz:
{ IS 2^g>T#1
processErrorCode(responseCode); <_tT<5'[$u
return -2; //-2 represent access is error Md2>3-
} YSh+pr
5$&%re!{Z
orfO^;qTY
String sHeader; /!$c/QZ
fM63+9I)\
K]0:?h;%Ld
for(int i=1;;i++) 4?7W+/~<&
{ ytoo~n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3.W@ }
//Utility.log(in.readLine()); 3#&7-o
sHeader=httpConnection.getHeaderFieldKey(i); |>htvDL
if(sHeader!=null) 6%Pdy$ P
{ Vz~nT
if(sHeader.equals("Content-Length")) (Cd\G=PK
{ J/GSceHF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $[&*Bj11Yg
break; G<f@#[$'
} af+IP_6 .
} 80/F7q'tn
else .#Z%1U%P.
break; \r,Q1n?7
} Rh{zH~oZ
} 7-T{a<g
catch(IOException e){e.printStackTrace ();} A1#%`^W9
catch(Exception e){e.printStackTrace ();} #+5pgD2C
aL%AQB,
{{MRELipW
Utility.log(nFileLength); DRgTe&+
ul2")HL];
CS-uNG6
return nFileLength; ayD}r#7
} }mdAM6
,Bo>E:u
H77"
//保存下载信息（文件指针位置） .CU5}Tv-
private void write_nPos() mkF"
{ qX
try{ Boz@bl mCB
output = new DataOutputStream(new FileOutputStream(tmpFile)); wl$h4 {L7
output.writeInt(nStartPos.length); &n?^$LTPY
for(int i=0;i<nStartPos.length;i++) 9;Ox;;w
{ :Q_<Z@2Y{
// output.writeLong(nPos); M9@ri^x
output.writeLong(fileSplitterFetch.nStartPos); TGe;HZ
output.writeLong(fileSplitterFetch.nEndPos); T{Uc:Z
} c|62jY"$-2
output.close(); okv1K
} C{DvD'^
catch(IOException e){e.printStackTrace ();} Dzs[GAQ]
catch(Exception e){e.printStackTrace ();} fCtPu08{Z
} 9Z'8!$LYg
q51Uf_\/
p)3U7"q
//读取保存的下载信息（文件指针位置） @u%_1
private void read_nPos() EC8b=B<DE
{ S.q].a
try{ ct,l^|0Hu8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WjwLM2<nK7
int nCount = input.readInt(); Ii_ojQP-z
nStartPos = new long[nCount]; 88h3|'*
nEndPos = new long[nCount]; ),!;| bh
for(int i=0;i<nStartPos.length;i++) F[[TWf/
{ GF%314Xu
nStartPos = input.readLong(); I{:(z3
nEndPos = input.readLong(); .j>hI="b
} /&{$ pM|?
input.close(); )!:Lzi
} lBFMwJU)
catch(IOException e){e.printStackTrace ();} q^L<X)
catch(Exception e){e.printStackTrace ();} qfz8jY]
} xD[Gq%
/iV}HV0
hcbv;[bG
private void processErrorCode(int nErrorCode) A\#P*+k0
{ o b|BXF
System.err.println("Error Code : " + nErrorCode); Y +\%
} yK2^Y]Ku?
'@CR\5 @
7C2&NyWJ
//停止文件下载 CL}{mEr}
public void siteStop() (B-43!C
{ `8>Py~
bStop = true; g9WGkHF
for(int i=0;i<nStartPos.length;i++) |{ PI102
fileSplitterFetch.splitterStop(); ['*8IWg
w{90`
z7Eg5rm|QZ
} g HbxgeL
} 6]pX>Xho
//负责部分文件的抓取 Y.U[wL>
**FileSplitterFetch.java R% ,<\d7
*/ Xy &uZ
package NetFox; V-r3-b
#\ n8M
0#*#a13
import java.io.*; ] 0m&(9
import java.net.*; 3lq Mucr
TkO[rAC
7ei|XfR
public class FileSplitterFetch extends Thread { 3^~KB'RZ
V{&rQ@{W
[mr9(m[F
String sURL; //File URL m7GR[MR
long nStartPos; //File Snippet Start Position u=/CRjot
long nEndPos; //File Snippet End Position pOkLb #
int nThreadID; //Thread's ID JiU9CeD3
boolean bDownOver = false; //Downing is over ?8mlZ X9C
boolean bStop = false; //Stop identical U}l14
FileAccessI fileAccessI = null; //File Access interface zf>5,k'x'A
C2w2252T
5W@jfh)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v[n7"
{ D.6,VY H
this.sURL = sURL; -+em!g'
this.nStartPos = nStart; 'EfR|7m
this.nEndPos = nEnd; hyT1xa
nThreadID = id; k8uvNLA)a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {E0z@D)U-
} LW:LFzp
D^;*U[F?
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public void run() zb Z4|_
{ 'vaLUy9]
while(nStartPos < nEndPos && !bStop) _:B1_rz7,
{ rzI|?QaPi
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Q9&kJ%Mo
try{ 3QOUU,Dt$
URL url = new URL(sURL); a9?y`{%L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?kz+R'
httpConnection.setRequestProperty("User-Agent","NetFox"); }AvcoD/b
String sProperty = "bytes="+nStartPos+"-"; N9<Ujom
httpConnection.setRequestProperty("RANGE",sProperty); h}Wdh1.M3
Utility.log(sProperty); 1uk0d`JL
3o|I[!2.
,mL !(US
InputStream input = httpConnection.getInputStream(); k%op> &
//logResponseHead(httpConnection); <JwX_\?ln
!;!~n`
b2b75}_A
byte[] b = new byte[1024]; +EM_TTf4
int nRead; &h,5:u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aRJ>6Q}
{ ?P7]u>H
nStartPos += fileAccessI.write(b,0,nRead); <(e8sNe
//if(nThreadID == 1) |J~eLh[d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CCGV~e+
} ACK1@eF
}V|{lvt.
sW^a`VM
Utility.log("Thread " + nThreadID + " is over!"); =_8Tp~j
bDownOver = true; `j9$T:`
//nPos = fileAccessI.write (b,0,nRead); m3g2b _;
} Q9`QL3LQD
catch(Exception e){e.printStackTrace ();} a%Jx `hx
} 5Y3i|cj
} -sMytHH.
8g>b
[!VOw@uz
//打印回应的头信息 U#o'H @
public void logResponseHead(HttpURLConnection con) 6R29$D|HFO
{ ='E$-_
for(int i=1;;i++) oQj=;[
{ Ij'NC C
String header=con.getHeaderFieldKey(i); 47T}0q,
if(header!=null) ^-M^gYBR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ._96*r=o
Utility.log(header+" : "+con.getHeaderField(header)); a/uo}[Y
else Z2bcCIq4
break; i$KpDXP\
} ]fI/(e_U
} 4E:bp
W];EKj,3W
&wetzC)
public void splitterStop() BD#.-xWV
{ e|r0zw S
bStop = true; ARfRsPxr
} k 2%S`/:
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cxYfZ4++m
} )OsLrq/
~ekh1^evu
vY*\R0/a
/* Yp4c'Zk
**FileAccess.java *V;3~x!
*//文件访问(定位，写) gK3Mms]}m
package NetFox; ;#G%U!p
import java.io.*; /LQ:Sv7
mi2o1"Jd$`
HpexH{.u)
public class FileAccessI implements Serializable{ )-/gLZsx
y$tX-9U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p11G#.0
RandomAccessFile oSavedFile; &4$oudn
long nPos; WO,xMfK
[ev-^[
cVq}c?
public FileAccessI() throws IOException '?Iif#Z1
{ <V_7|)'/A
this("",0); >AI<60/<
} *N/hc
,dd WBwMK
aN^IP
public FileAccessI(String sName,long nPos) throws IOException hGP1(pH.
{ Vul+]h[!h
oSavedFile = new RandomAccessFile(sName,"rw"); q3'o|pp
this.nPos = nPos; fV ZW[9[
oSavedFile.seek(nPos); |Zq\GA
} xNN@1P[*
hWcTI{v
i.rU&yT%
public synchronized int write(byte[] b,int nStart,int nLen) z4} %TT@^
{ hPufzhT
int n = -1; D(r:}pyU
try{ G"S5ki`o
oSavedFile.write(b,nStart,nLen); Kv+Bfh
n = nLen; e4qj .b
} ibF#$&!
catch(IOException e) S@:B6](D$
{ U 0ZB^`
e.printStackTrace (); :LV.G0)#
} <Ns &b.\h6
>v0:qN7|
{&nV4c$v
return n; \/Ij7nD`l%
} MMD<I6Iyv
,{j4
+*t|yKO>[
} TV{)n'aA
t^@T`2jL
c#q"\"
/* 6d{j0?mM
**SiteInfoBean.java ?TuI:dC
*/ "]]q} O?
package NetFox; d]M[C[TOX
2X@G"
%N~;{!![p
public class SiteInfoBean { "oE*9J?e
K~>jApZ%
~5t?C<wo
private String sSiteURL; //Site's URL xtJAMo>g
private String sFilePath; //Saved File's Path !O\X+#j
private String sFileName; //Saved File's Name $au2%NL
private int nSplitter; //Count of Splited Downloading File {of]/3=
0:dB 9
xYR#%!M
public SiteInfoBean() vbn>mg5
{//nSplitter的缺省值为5 a8h]n:!
//default value of nSplitter is 5 G6Q4-kcK
this("","","",5); `Ei"_W
} m,NMTyJoz
Mj~${vj
`45d"B I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) POBpJg
{ piu0^vEEH
sSiteURL= sURL; `$9L^Yg,4
sFilePath = sPath; 31 ]7z
sFileName = sName; 4Vx+[8W
this.nSplitter = nSpiltter; 9U10d&M(
YY!!<2_
9N}W(>
} =QiT)9q)
P{lh)m>
j<$R4A1
public String getSSiteURL() f8!l7{2%q
{ @9_)On9hZ
return sSiteURL; p}8ratmN
} WTu{,Q
v>^jy8$
|+/$ g.
public void setSSiteURL(String value) )_O.{$ to
{ Y\u_+CG*
sSiteURL = value; /.-m}0h|W-
} aL$j/SC
B*Cb6'Q
4sd-zl$Of
public String getSFilePath() U$$3'n
{ 8DT@h8tA
return sFilePath; ?zE<
} 4[H,3}p9H
-wIM0YJ
R`7n^,
public void setSFilePath(String value) c'lIWuL)
{ B'/Icg.T
sFilePath = value; X)NWX9^;'
} t>@yv#
D'?]yyrf
\I xzdFF#
public String getSFileName() Wy,"cT
{ w#d}TY
return sFileName; mdt ?:F4Q
} 2?H@$-x>
T Xl\hL\+
L)G">T;
public void setSFileName(String value) r &c_4%y
{ Hc /wta
sFileName = value; Fi k@hu
} Q^q=!/qQ
j%GbgJ
{"\q(R0
public int getNSplitter() N I3(
{ *e,CDV
return nSplitter; YrKFa%k
} 5EfY9}dl
S r[IoF)
9 G((wiE
public void setNSplitter(int nCount) z.A4x#>-
{ k2wBy'M.'
nSplitter = nCount; j>V"hf
} (mY(\mu}
} -|$*l Q
0.(zTJ
_AAx )
/* 3v G
**Utility.java w=gQ3j#s
*/ U!_sh<
package NetFox; 7~lB}$L
NB3/A"}"02
`lvh\[3^
public class Utility { sV&`0N
&8juS,b
78^Y;2 P]W
public Utility() l4DeX\ly7f
{ SUSc
0ZFB4GL
^U" q|[qy
} Vzk cZK
B_b8r7Vn`
//线程睡眠 d[yrNB6|
public static void sleep(int nSecond) r \9:<i8
{ i~(#S8U4d
try{ 69?I?,7
Thread.sleep(nSecond); Bac?'ypm
} _RgxKp/d
catch(Exception e) `$f\ %
{ %d ZM9I0
e.printStackTrace (); JPHUmv6
} a{5H33JA
} kzW\z4f
\8 g.
//日志 [6oq##
public static void log(String sMsg) IBzHR[#,^
{ O5c_\yv=
System.err.println(sMsg); EP/&m|o|G
} 5wy;8a
fHW-Je7mG
%!>k#F^S
public static void log(int sMsg) s}Xi2^x
{ -%saeX Wo
System.err.println(sMsg); d4[poi ~
} 2f s9JP{^0
} `x5ll;"J
$Gr4sh!cE
}FuVY><l
/* v4X_v!CQ
**TestMethod.java 1w(<0Be
*/ 1 VPg`+o
package NetFox; U<1}I.hDJ
+'!h-x1y~
:17ee
public class TestMethod { $0ym_6n
BYTXAZLb
:t_}_!~
public TestMethod() ;D6x=v=2
{ ///xx/weblogic60b2_win.exe @2QJm
try{ wEZqkV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p!. /
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _a?wf!4>P
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q1]V|S;)X
fileFetch.start(); ]Fb8.q5(Y
} s$IcDuBu
catch(Exception e){e.printStackTrace ();} ~oEXM?M
Xcs8zT
wOD/Z8
} X%RQB$
PEMxoe<+
|p'_k(z}
public static void main(String[] args) h[vAU 9f)
{ ke{DFqh
new TestMethod(); $Vd?K@W[h
} qb#V)
} _SU,f>
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