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)); vp-7>Wj
} [oLQd-+
for(int i=0;i<nEndPos.length-1;i++) XS8~jBjx
{ j9'XZq}
nEndPos = nStartPos[i+1]; X@U1Ri
} :<k|u!b}y
nEndPos[nEndPos.length-1] = nFileLength; c0q)
} 4!vUksM
} O7'3}P;
@n*D>g
k=2l9C3Z
//启动子线程 _PUm Pom.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gj`Y2X2r
for(int i=0;i<nStartPos.length;i++) N09+idg
{ Mk/!,N<h#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i03}f%JnuO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^jjJM|a
nStartPos,nEndPos,i); pm@Z[g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x*8f3^ wE
fileSplitterFetch.start(); E(kpK5h{
} O>M*mTM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #UCQiQfP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yVQz<tX|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R+VLoz*J6
nEndPos = " + nFileLength); \Rqh|T<D
// fileSplitterFetch[nPos.length-1].start(); N3p 7 0
."Ix#\|x
g*?+~0"`Y
//等待子线程结束 =GKYroNM
//int count = 0; GtJ*&=(
//是否结束while循环 $1zeY6O
boolean breakWhile = false; 'O2#1SWe
XW_xNkpL5c
Tv,.
while(!bStop) 9$V_=Bo
{ VfqY_NmgC
write_nPos(); a {$k<@Ww
Utility.sleep(500); 0k0c
breakWhile = true; iz>y u[|
.L5*E(<K0
y<%.wM]-J
for(int i=0;i<nStartPos.length;i++) )]?egw5l
{ .4re0:V
if(!fileSplitterFetch.bDownOver) i~B@(,
{ =#2qX>?
breakWhile = false; ^}/ E~Sg7\
break; 3r:)\E+Q_
} *r,&@UB
} <&s)k
if(breakWhile) w[7.@%^[
break; J*~2:{=%
gq_7_Y/
A='+tJa
//count++; dwbY"t[9
//if(count>4) *RbOQ86vP
// siteStop(); UoMWn"ZE
} W;oU +z^t$
x$?7)F&z
LF)a"Sh
System.err.println("文件下载结束！"); Y:!/4GF
} xCp+<|1
catch(Exception e){e.printStackTrace ();} ?~JxO/K
} MRg\FR2>1
|8qK%n f}
N' $DE
//获得文件长度 v7<S F
public long getFileSize() 5*wApu{2A
{ h9BD ^j
int nFileLength = -1; 'Rkvsch
try{ r;on0wm&B
URL url = new URL(siteInfoBean.getSSiteURL()); CziaxJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x"llX
httpConnection.setRequestProperty("User-Agent","NetFox"); JdUz!=I
B?lBO V4v4
g3~~"`2
int responseCode=httpConnection.getResponseCode(); :O'C:n<g
if(responseCode>=400) Uq]EJu
{ 9p\Hx#^
processErrorCode(responseCode); MHnf\|DX
return -2; //-2 represent access is error Dj ]Hgg
} mj~N]cxB
y }&4HrT&
<% 7P
String sHeader; }y-;>i#m=g
| 2.e0Z]k
e8ULf~I
for(int i=1;;i++) o~o6S=4,}
{ cbu nq"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,+\4 '`
//Utility.log(in.readLine()); *0&4mi8
sHeader=httpConnection.getHeaderFieldKey(i); by|?g8
if(sHeader!=null) 9 yW~79n
{ N5f0|U&
if(sHeader.equals("Content-Length")) tf7v5iGe
{ #7~tL23}]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I*:qGr+ WJ
break; J|"nwY}a9
} s la*3~?*
} ])QO%
else jV4hxuc$
break; VM!-I8t
} ~N{_N95!2@
} uhTKCR~
catch(IOException e){e.printStackTrace ();} t(j_eq}J
catch(Exception e){e.printStackTrace ();} ,a9D~i 9R
*dG}R#9Nv
FYXw$7'l
Utility.log(nFileLength); T\2) $
;zZ,3pl-E
o%Uu.P
return nFileLength; > h,y\uV1
} N /sEec
2Ft8dfdm`
k(-Z@
//保存下载信息（文件指针位置） CQBT::
private void write_nPos() $^vp'^uW>
{ J@ktj(
try{ Z:UgozdC
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'NT#(m%
output.writeInt(nStartPos.length); @)OnIQN~
for(int i=0;i<nStartPos.length;i++) ~@-QbkC
{ Tsm1C#6 Y*
// output.writeLong(nPos); JNxW6 cK
output.writeLong(fileSplitterFetch.nStartPos); UzU-eyA
output.writeLong(fileSplitterFetch.nEndPos); q,;".3VQ
} W$JY M3!
output.close(); :cXIO
} Avs7(-L+s
catch(IOException e){e.printStackTrace ();} 8S.')<-f
catch(Exception e){e.printStackTrace ();} W+d9cM=
} ~A[YnJYA#
8/Et&TJ`
IOsXPf9@
//读取保存的下载信息（文件指针位置） ?JXBWB4
private void read_nPos() 670J{b
{ pAJ=f}",]E
try{ j*;*Ka w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %;pD8WgJA
int nCount = input.readInt(); C 'B4 mmC
nStartPos = new long[nCount]; j<l#qho{h
nEndPos = new long[nCount]; k Zk .]b
for(int i=0;i<nStartPos.length;i++) !y>lOw})Q
{ yfSiByU
nStartPos = input.readLong(); DC$7B`#D
nEndPos = input.readLong(); 6C:x6'5[
} kf+JM/
input.close(); q3c*<n g#
} Yw~;g:=
catch(IOException e){e.printStackTrace ();} ",~ b2]ym
catch(Exception e){e.printStackTrace ();} ]PR|d\O
} K,x$c %
tr}KPdE
PoYr:=S?
private void processErrorCode(int nErrorCode) 2j8Cv:{Nn%
{ sTKab :
System.err.println("Error Code : " + nErrorCode); 'v'` F*6
} xNC* ]8d
-d|BO[4j
5wzQ?07T_
//停止文件下载 Hi]vHG(
public void siteStop() ojN`#%X
{ a);O3N/*I
bStop = true; { A:LAAf[6
for(int i=0;i<nStartPos.length;i++) H/^~<U#p
fileSplitterFetch.splitterStop(); _, \y2&KT
(g%JK3
]~?S~l%
} 5"1!p3`\D{
} /yx=7<
//负责部分文件的抓取 Jq#[uX
**FileSplitterFetch.java 8_"3Yb`f
*/ "NxOOLL
package NetFox; J*}VV9H
ijvNmn1k
r@|R-Binz
import java.io.*; m3U+ du
import java.net.*; ^D9 /
-,R0IGS
nHI(V-E2:H
public class FileSplitterFetch extends Thread { >:.w7LQy/
xh{mca>?G
5>'?:jY
String sURL; //File URL fkW3~b
long nStartPos; //File Snippet Start Position ,"@w>WL<9
long nEndPos; //File Snippet End Position (3AYy0J%
int nThreadID; //Thread's ID rQ=xcn[A
boolean bDownOver = false; //Downing is over MPjr_yc]
boolean bStop = false; //Stop identical hA@zoIoe
FileAccessI fileAccessI = null; //File Access interface nped
lN);~|IOv7
?$<SCN=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d-hbvLn
{ XXXljh6
this.sURL = sURL; s0gJ f[
this.nStartPos = nStart; n)tU9@4Np
this.nEndPos = nEnd; B:e.gtM5
nThreadID = id; vAi"$e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vz6SCGg,
} &K06}[J
kXigX-
b+W)2rFO
public void run() XlRw Z/Wc
{ W7%p^;ZQ$
while(nStartPos < nEndPos && !bStop) HpW"lYW4
{ T48BRVX-F
F\;2i:(
]AFj&CteZ/
try{ !K!)S^^Po?
URL url = new URL(sURL); -_s%8l^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DD2adu^
httpConnection.setRequestProperty("User-Agent","NetFox"); o(:{InpV%A
String sProperty = "bytes="+nStartPos+"-"; !{$qMhT
httpConnection.setRequestProperty("RANGE",sProperty); mRwXN*Izw
Utility.log(sProperty); :}^Rs9 '
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dI!8S
InputStream input = httpConnection.getInputStream(); w"q-#,37j
//logResponseHead(httpConnection); +IvNyj|
6@&fvf
n.@#rBKZ
byte[] b = new byte[1024]; aZP2R"
int nRead; kl| g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3*G5F}7%=
{ jz|VF,l
nStartPos += fileAccessI.write(b,0,nRead); Cm^Ylp
//if(nThreadID == 1) HB%K|&!+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7@JjjV
} 6j_ 678
miwf&b
aXC!t
Utility.log("Thread " + nThreadID + " is over!"); yGRR8F5>(
bDownOver = true; M/*Bh,M`
//nPos = fileAccessI.write (b,0,nRead); (m6EQoW^s+
} 8IeI0f"l)
catch(Exception e){e.printStackTrace ();} '[%jjUU
} [@ILc*2O
} 3]N q@t
wXz\NGW
>A<Df
//打印回应的头信息 *E.LP1xP
public void logResponseHead(HttpURLConnection con) +.=1^+a
{ U4=]#=R~o
for(int i=1;;i++) NJk)z&M
{ AHq M7+r9
String header=con.getHeaderFieldKey(i); Is ot4HLM
if(header!=null) iZC>)&ax
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KVg[#~3
Utility.log(header+" : "+con.getHeaderField(header)); ?gU}[]
else _wmI(+_
break; xg?auje
} }*h47t}
} DjY8nePyE
P`tyBe#=
\Fq1^ 8qa
public void splitterStop() hv3;irK]&
{ <Kg2$lu(_`
bStop = true; >}CEN
} @`6}`k
.wP/ai>}
e#1.T
} alVdQfu
3EI]bmi~
S.1(3j*
/* 7H4L-J3
**FileAccess.java Y|_O8[
*//文件访问(定位，写) ]Y{,Nx
package NetFox; =x1Wii$`
import java.io.*; #,TELzUVE
-;vT<G3
0 k9<&
public class FileAccessI implements Serializable{ se#@)LtZ
&~'S)Nun
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [z2eCH
RandomAccessFile oSavedFile; S!`:E
long nPos; VNO'="U
\X5 3|Y;=
';Nu&D#Ph
public FileAccessI() throws IOException _W}(!TKO
{ ^zgacn
this("",0); ?,>5[Ha^?
} 8TW5(fl
Cs#w72N
JYQ.EAsr!
public FileAccessI(String sName,long nPos) throws IOException )nOE8y/
{ ctHEEFWm
oSavedFile = new RandomAccessFile(sName,"rw"); F{\=PCZ>7
this.nPos = nPos; @y5=J`@=
oSavedFile.seek(nPos); =DC3a3&%
} ~;8I5Sge
x}|+sS,g
FfG%C>E6~
public synchronized int write(byte[] b,int nStart,int nLen) V9Hl1\j^
{ .;g}%C
int n = -1; IT18v[-G
try{ rI>LjHP
oSavedFile.write(b,nStart,nLen); y6FKg)
n = nLen; )b9_C O}
} r8,om^N6
catch(IOException e) @D]lgq[
{ yPN+W8}f
e.printStackTrace (); W~yLl%
} s&VOwU
`BjR.xMv
Zw#<E =\
return n; |mOMRP#'
} :v)6gz(p
L#2ZMy
Bzw19S6y
} {[P!$ /
M*(H)i;s:w
\7 Gz\=\LR
/* tF%QH[
**SiteInfoBean.java uXpv*i{R
*/ '%&z.{
package NetFox; @vt$MiOi
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,56;4)cv
public class SiteInfoBean { WqQU@sA
$UC{"0
/NU103F yt
private String sSiteURL; //Site's URL ke]Yfwk
private String sFilePath; //Saved File's Path G?ig1PB"#
private String sFileName; //Saved File's Name {m[Wyb(
private int nSplitter; //Count of Splited Downloading File n}q$f|4!
0X>T+A[E
uY]0dyI
public SiteInfoBean() |'$ l7
{//nSplitter的缺省值为5 ?oKL&I@
//default value of nSplitter is 5 I .P6l*$
this("","","",5); NbkK&bz
} 'Wp@b678
dp<$Zw8BE
vBoO'l9'M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9yL6W'B!
{ \=fh-c(J,
sSiteURL= sURL; q:]Q% IC^
sFilePath = sPath; m#n]Wgp'
sFileName = sName; 8wmQ4){
this.nSplitter = nSpiltter; x<>YUw8`
P)hi||[
;_N5>3C:
} aq$q ~,E
p[qg&VKB
yWY|]Pp
public String getSSiteURL() J>h;_jA
{ EEwWucQ
return sSiteURL; c1#+Vse
} 7n&yv9"
p+Lv=e)0u
2*'ciH37
public void setSSiteURL(String value) ]0-<>
{ sLhDO'kM
sSiteURL = value; zJCEA
} KGT3|)QN
`eD1|Go9
MI*Sq\-i
public String getSFilePath() &F6C
{ :0I l|aB
return sFilePath; Q0>q:aj\
} 'RLOV
CXAVGO'xw
|}Ph"g2D,
public void setSFilePath(String value) &,MFB
{ m\-PU z&C
sFilePath = value; s)w9%
} X<euD9?
mb{q(WEPP
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public String getSFileName() ~ffwLgu!
{ Mudrg[@`
return sFileName; JA6";fl;
} :<utq|#s
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wW5Yw i
public void setSFileName(String value) i/$SN-5}1
{ ,YB1 y)x
sFileName = value; |^Kjz{
} .8H}Lf\
8xTix1u0
vYnftJK&
public int getNSplitter() >>7aw" 0
{ BY( eV!
return nSplitter; uJ8{HB
} |GuEGmR
(/?R9T[V&^
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public void setNSplitter(int nCount) 2w4MJ,Uw
{ Dbz]{_Y;
nSplitter = nCount; 0roCP=;
} QO,+ps<
} Ac\W\=QvB
<|H?gfM
WQKj]:qk0
/* /gw Cwyo
**Utility.java %rcFT_
*/ T4GW1NP
package NetFox; N`1r;%5
VMHC/jlX@r
Zi4d]
public class Utility { =DMbz`t
28oJFi]
UvBnf+,
public Utility() ug&92Hdvy3
{ ny1 \4C
tlGWl0V?7Q
it,w^VU_]
} 7zGMkl
&yLc1#H
//线程睡眠 O?E6xc<8
public static void sleep(int nSecond) TSQhX~RN
{ Tl3"PIb
try{ 6K 4+0xXv
Thread.sleep(nSecond); YoAg
} f:vD`Fz1
catch(Exception e) RIjM(P
{ D]u=PqHk2
e.printStackTrace (); *P xf#X
} #T"64%dX
} QJSr:dP4dG
;BVDt
//日志 } yq
public static void log(String sMsg) euZI`*0
{ -3vh!JMN
System.err.println(sMsg); 968^"T#
} ,sI35I J
$?f]ZyZr.
=P]GPEz_
public static void log(int sMsg) !nzGH*td
{ PEzia}m
System.err.println(sMsg); @?a4i
} W~NYU
} }n[Bq#
7I3:u+
Jck"Ks
/* kl<g;3
**TestMethod.java ) ,Npv3(
*/ 2.qpt'p[
package NetFox; 0N5bPb
!Uy>eji}
)!,@m>0v{
public class TestMethod { j38 6gL
+c?ie4
7K:FeW'N
public TestMethod() all*P #[X
{ ///xx/weblogic60b2_win.exe CQ18%w6
try{ iZC`z }
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X6kaL3L}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |Puj7Ru
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0jTMZ<&zZ
fileFetch.start(); j_c+.iET
} OjATSmZ@@
catch(Exception e){e.printStackTrace ();} FmI;lVF0j
<kbnu7?a*
q+%!<]7X
} UkfA}b^@v
b1)\Zi
v,0<9!'v
public static void main(String[] args) })7K S?
{ /7vE>mSY
new TestMethod(); 0WXVc
} **HrWM%?8o
} !NA`g7'
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