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)); QE1DTU
} #**vIwX-Q
for(int i=0;i<nEndPos.length-1;i++) 3!ZndWSHV
{ A@^Y2:pY
nEndPos = nStartPos[i+1]; d#'aTmu!
} *DcJ).
nEndPos[nEndPos.length-1] = nFileLength; :_X9x{
} (< gk<e*
} gZ8n[zxf6
hi^@969
ju~js
//启动子线程 Sxa+"0d6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \4zb9CxOZ
for(int i=0;i<nStartPos.length;i++) O0[.*xG
{ 2|8e7q:+*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hx5t![g2K!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ckG`^<
nStartPos,nEndPos,i); 9)}Nx>K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vau0Jn%=ck
fileSplitterFetch.start(); 3Uw}!>`%
} {a;my"ly
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c0h:Vqk-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dz3chy,3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .93B@u
nEndPos = " + nFileLength); 2j*;1
// fileSplitterFetch[nPos.length-1].start(); d[eN#<
KG=h!]Meq
(r78AZ
//等待子线程结束 qRC-+k:
//int count = 0; m_ >+$uL
//是否结束while循环 HY|=Z\l"
boolean breakWhile = false; 2B Dz \
9O1#%
C{^U^>bU
while(!bStop) HuzHXn)
{ Gpv9~&
write_nPos(); (CDwl,
Utility.sleep(500); XqX6UEVR4
breakWhile = true; \qk+cK;+
apFY//(yu
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for(int i=0;i<nStartPos.length;i++) F6,[!.wl
{ ) bRj'*
if(!fileSplitterFetch.bDownOver) ;]XKe')
{ G>Uam TM
breakWhile = false; xd }g1c
break; e!BablG[
} walQo^<
} ]N<:6+
if(breakWhile) :jo !Yi
break; 9OI&De5?=V
b9FfDDOq"
fdk]i/*)
//count++; H& L
//if(count>4) AXBf\)[
// siteStop(); /-J12O
} $=) i{kGS@
:s(vn Ie^
1FC' iGI
System.err.println("文件下载结束！"); 1j4(/A
} UM[<v9NWE
catch(Exception e){e.printStackTrace ();} 0{0BL@H
} ^6c=[N$aW
?7n(6kmj4Q
uj 6dP
//获得文件长度 E6 glR
public long getFileSize() -`knSR
{ `GGACH3#s
int nFileLength = -1; k(As^'>
try{ 1"7Rs}l7
URL url = new URL(siteInfoBean.getSSiteURL()); e&*< "WN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |^ K"#K
httpConnection.setRequestProperty("User-Agent","NetFox"); q4Z9;^S
e;_ cC7
wlvhDJ
int responseCode=httpConnection.getResponseCode(); e[`u:
if(responseCode>=400) AiMD"7 )c
{ E}&Z=+v}
processErrorCode(responseCode); F^knlv'
return -2; //-2 represent access is error b d!|/Lk
} 0qND2_
k#*tf:R
/1s|FI$-L
String sHeader; 4^|;a0Qy]
~D[5AXV`^
@t W;(8-
for(int i=1;;i++) UM?{ba9
{ CY{`IZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4&TTPcSt;
//Utility.log(in.readLine()); !4gyrNS
sHeader=httpConnection.getHeaderFieldKey(i); UBN^dbP*
if(sHeader!=null) /<J&ZoeJB
{ qhNY<
if(sHeader.equals("Content-Length")) S4qj}`$ Yv
{ d`M]>EDXp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zzq7?]D
break; \(m_3 H
} -&3WN!egq
} H?ZlJ|/c
else 7F=Xn@ _
break; EKwA1,Xz
} : 5=E>!
} X}!r4<;(
catch(IOException e){e.printStackTrace ();} !sbKJ+V7
catch(Exception e){e.printStackTrace ();} 4d\"gk
HkgmZw,
X^pxu6nm-
Utility.log(nFileLength); bu&x& M*
oSDx9%
Uwd^%x*
return nFileLength; Lbo8>L(
} G|WO
lz=DP:/&
&PfCY{_
//保存下载信息（文件指针位置） f{]eb1
private void write_nPos() Km)5;BQxg
{ $M `%A
try{ w>RBth^p
output = new DataOutputStream(new FileOutputStream(tmpFile)); a-P'h1hbH
output.writeInt(nStartPos.length); "ZuhN(-`
for(int i=0;i<nStartPos.length;i++) -85]x)JE
{ ~hJ/&,vH!
// output.writeLong(nPos); u!iBAr5
output.writeLong(fileSplitterFetch.nStartPos); J|ni'Hb
output.writeLong(fileSplitterFetch.nEndPos); ubq4Zv7'
} hN~]$"@2
output.close(); *Ey5F/N}$H
} ,(%?j]_P2
catch(IOException e){e.printStackTrace ();} <4caG2~q
catch(Exception e){e.printStackTrace ();} #1>DV@^F
} q(N2#di
|sa{!tKJ
pt`^4}
//读取保存的下载信息（文件指针位置） iti~RV,
private void read_nPos() QH_0U`3
{ pI__<
try{ l?_h(Cq<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '/Y D$*,
int nCount = input.readInt(); OK=lp4X
nStartPos = new long[nCount]; 8XwZJ\5
nEndPos = new long[nCount]; "X\|!Mxh
for(int i=0;i<nStartPos.length;i++) X)-9u8
{ .I6:iB
nStartPos = input.readLong(); "K.XoG4|
nEndPos = input.readLong(); Nk~Xz
} $Vu%4kq
input.close(); a!`b`r-4
} 1KH]l336D"
catch(IOException e){e.printStackTrace ();} D4CN%^?
catch(Exception e){e.printStackTrace ();} t>W^^'=E
} +Lq;0tRC
VxlK:*t`
994
private void processErrorCode(int nErrorCode) ."N`X\
{ x2P}8Idg?A
System.err.println("Error Code : " + nErrorCode); me-:A:si
} /3MTutM|<X
lnXb]tm;
HwE1cOT
//停止文件下载 r*-e~
public void siteStop() H9c
{ }~8/a3
bStop = true; nG0Uv%?{pj
for(int i=0;i<nStartPos.length;i++) c&A;0**K,
fileSplitterFetch.splitterStop(); /EJwO3MW
(IAc*V~
0SoU\/kUi
} W{0gtT0
} =y5~7&9'
//负责部分文件的抓取 V}leEf2'
**FileSplitterFetch.java cfb8kNn~+
*/ XM0;cF
package NetFox; 1 \#n{a3
UfE41el:
@<GVY))R8
import java.io.*; ?q}XDc
import java.net.*; 9u3~s<
.JR"|;M}
1QfOD-lv
public class FileSplitterFetch extends Thread { >JNK06T
SvlS4C
b!>w4MPe
String sURL; //File URL n+5X*~D
long nStartPos; //File Snippet Start Position Ol;}+?[Q
long nEndPos; //File Snippet End Position k\:f2%!!
int nThreadID; //Thread's ID 1|4'3^3
boolean bDownOver = false; //Downing is over |2yTt*!-r
boolean bStop = false; //Stop identical 1[QH68
FileAccessI fileAccessI = null; //File Access interface $VX<UK$|s
TEgmE9^`)7
B3p[A k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j Hd<*
{ %h"+J
this.sURL = sURL; ^7l.!s#$b
this.nStartPos = nStart; [+=h[DC
this.nEndPos = nEnd; V;b^b5yZ>
nThreadID = id; _g%Wx?K9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ELx?ph-9
} m?Gb5=qo
!&~8j7{
?V6+o`bm
public void run() QlbhQkn
{ G4!$48
while(nStartPos < nEndPos && !bStop) (#w8/@JxF
{ Z19d Ted33
UOWOOdWSB
*{5L*\AZ
try{ @2mJh^cj
URL url = new URL(sURL); zTFfft<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s+"[S%
httpConnection.setRequestProperty("User-Agent","NetFox"); HJY_l
String sProperty = "bytes="+nStartPos+"-"; {J:ZM"GS
httpConnection.setRequestProperty("RANGE",sProperty); =4RBHe8`
Utility.log(sProperty); F",S}cK*MH
\wmNeGC2
%cM2;a=2
InputStream input = httpConnection.getInputStream(); !ul)e;a
//logResponseHead(httpConnection); Sb&sW?M
)^&,[Q=i
Zi+>#kDV
byte[] b = new byte[1024]; cZ(7/Pl
int nRead; b;!oPT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _8Si8+j
{ }2sc|K^
nStartPos += fileAccessI.write(b,0,nRead); 8aCa(Xu(H
//if(nThreadID == 1) O5PCR6U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cJ 5":^O
} i!/V wGg
Z`fm;7NiVG
NT~L=xsY
Utility.log("Thread " + nThreadID + " is over!"); W\{gBjfE
bDownOver = true; O,Xf.O1c
//nPos = fileAccessI.write (b,0,nRead); MC5M><5\
} k~ZwHx(%S
catch(Exception e){e.printStackTrace ();} &A=q_
} _ ?f~UvK
} ~%Y*2i f
_7SOl.5ZE
M) 9Ss
//打印回应的头信息 8-cB0F=j_
public void logResponseHead(HttpURLConnection con) a#X[V5|6Q
{ 2?LZW14$d
for(int i=1;;i++) ArBgg[i
{ \h6_m)*H4
String header=con.getHeaderFieldKey(i); e_6@oh2s-
if(header!=null) V Iof4?i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C\7qAR\
Utility.log(header+" : "+con.getHeaderField(header)); cdL$T6y
else <Bc J;X/
break; mw<LNnT{8
} w'q}aQS
} @DT${,.49
~ifo7,
`0+zF-
public void splitterStop() A7.$soI\
{ .M_[tl
bStop = true; Q!Rknj 2
} 3=!\>0;E-
9N>Dp N
Y_&D W4
} [`P+{ R
(o_w[jv
XW6>;:4k
/* PTe8,cD>
**FileAccess.java -#v1b>ScY
*//文件访问(定位，写) =@b/Gl
package NetFox; 3_(fisvx
import java.io.*; n!mtMPH$
[Q,E( s
#RoGyrLo
public class FileAccessI implements Serializable{ rlYAy5&
Q4Mp[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T78`~-D4<
RandomAccessFile oSavedFile; l]whL1N3
long nPos; TD+V.}
2<Pi2s'
vMJv.O>HW
public FileAccessI() throws IOException tk4~ 8
{ yG?,8!/]
this("",0); /jih;J|
} #SQao;>
4os7tx
Wa~'p+<c~b
public FileAccessI(String sName,long nPos) throws IOException pR2QS
{ E1:{5F5/
oSavedFile = new RandomAccessFile(sName,"rw"); b,YTw
this.nPos = nPos; /N+*=LIK I
oSavedFile.seek(nPos); ]Y;EIn
} \R45#. P6X
6sb,*uSn%
`,ZsKxI
public synchronized int write(byte[] b,int nStart,int nLen) M xUj7ae
{ [E_6n$w
int n = -1; ?4wS/_C/
try{ NKd!i09`
oSavedFile.write(b,nStart,nLen); $Jo[&,
n = nLen; q#Az\B:
} KumbG>O
catch(IOException e) uArs[e|f
{ [Y.3miE
e.printStackTrace (); W0eb9g`s
} -Cv:lJj
$6 \v1
%qRbl4
return n; cYyv iR59#
} aS?A3h4WM_
+`l>_u'
)r-t$ L
} uiDK&@RS
%"V Y)
xlF$PpRNM
/* t_c;4iE
**SiteInfoBean.java Qjh5m5e
*/ 8D[P*?O
package NetFox; &;5QB
6rMGlzuRo
D]v=/43
public class SiteInfoBean { =mYY8c Yl
)s1W)J?8
|lAu6d !
private String sSiteURL; //Site's URL r>4.{\C
private String sFilePath; //Saved File's Path jgbUZP4J>
private String sFileName; //Saved File's Name <*0^X%Vf\
private int nSplitter; //Count of Splited Downloading File ,tv P"@d
fk,[`n+
.BJ;}
public SiteInfoBean() m&jh7)V
{//nSplitter的缺省值为5 Y~(#_K
//default value of nSplitter is 5 to9 u%d8
this("","","",5); k$?zh$
} 8r(S=dA
i]gF 6:&
Ko9"mHNB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~{'.9
{ 4FEOV,n
sSiteURL= sURL; IQxY]0\uf6
sFilePath = sPath; %M^X>S\%
sFileName = sName; #DpDmMP9R3
this.nSplitter = nSpiltter; Qy`{y?T2
+CtsD9PA
.%;UP7g
} d:}aFP[
/10 I}3D
B P%>J^
public String getSSiteURL() Ss+e*e5Ht
{ k!Nl#.j
return sSiteURL; bIt%KG{PY6
} poj@G{
&yN@(P)
v??}d
public void setSSiteURL(String value) 7k}[x|u
{ -S\74hA
sSiteURL = value; Z?|\0GR+`5
} B'>(kZYMs
Q9=vgOW+
:$j6
public String getSFilePath() #`)zD"CO
{ o%X@Bz
return sFilePath; :a#Mq9ph!
} bS_fWD-
p6u"$)wt
|&lAt\
public void setSFilePath(String value) 9{\eE]0
{ w?]k$
sFilePath = value; %4?
} <<!XWV*m
pJ-/"Q|:i
z(L\I
public String getSFileName() [xq"[*Evv
{ &(3kwdI
return sFileName; >7. $=y8b
} ;*ebq'D([
B]~#+rMK
`G> 6
public void setSFileName(String value) #R v&b@K
{ R4v)}`x
sFileName = value; EeC5HgIU'C
} ;|&Ak_I2G
YFgQ!\&59
OnFx8r:q@%
public int getNSplitter() AHX_I
{ pH5"g"e1
return nSplitter; vk:@rOpl
} nf?;h!_7
Cp(,+dD
>:%YAR`
public void setNSplitter(int nCount) o\u31,
{ +O>1Ed
nSplitter = nCount; \hv1"WaJ
} 1c_qNI;:p
} J&4LyIpQ
1~NXCIdF
i~:FlW]
/* .n1]Yk;,1
**Utility.java !~PLW]Z4
*/ 1^rODfY0
package NetFox; ?zp@HSa9
uSp=,2)
gK7j~.bb"
public class Utility { N}Ozm6Mc
+~mBo+ ,
zB`)\
public Utility() e{@TR x
{ P[-2^1P"
5\/h3i"I
rSDS9Vf(
} B]oIFLED
gn"_()8cT
//线程睡眠 q5J6d+
public static void sleep(int nSecond) ;B>2oq
{ E8#r<=(m
try{ so_
Thread.sleep(nSecond); +o})Cs`|=A
} i9fK`:)
catch(Exception e) %toxZ}OP
{ "Wd?U[[
e.printStackTrace (); C'3/B)u}l
} 4jEPh{q
} j&)"a,f
J/Ki]T9
//日志 d54(6N%
public static void log(String sMsg) 4hwUH
{ 0kP,Zj<
System.err.println(sMsg); &qqS'G*
} Pda(O;aNU
&A>Hq/Y
Y0iL+=[k`m
public static void log(int sMsg) UV8,SSDTV
{ l9 RjxO.~U
System.err.println(sMsg); Z=`\U?,
} m5Gt8Z 6a
} #UGm/4C
RkP g&R;i
v WKUV|
/* tj@IrwC^e"
**TestMethod.java 5at\!17TY
*/ ;i|V++$_
package NetFox; 6Ouy%]0$I3
._JM3o}F
|pk1pV |
public class TestMethod { D(6d#c
]l.y/pRP5[
:=x-b3U
public TestMethod() =BW>jD
{ ///xx/weblogic60b2_win.exe l(|@ dp
try{ ':6!f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OpeK-K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _ Js& _d
SiteFileFetch fileFetch = new SiteFileFetch(bean); FaO=<jYi
fileFetch.start(); HVG9 C$
} AK%2#}k.
catch(Exception e){e.printStackTrace ();} FaO1?.
f6n'g:&.W
IKSe X
} G3vKA&KZ
-Gjz;/s%XH
qD:3;85
public static void main(String[] args) bf]W_I]B
{ hQ`g B.DR
new TestMethod(); ;KqH]h)
} bm9@A]yP
} n`<YhV
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