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)); &\C{,:[
} (8r?'H8ZO
for(int i=0;i<nEndPos.length-1;i++) JHf}LZu
{ BX),U
nEndPos = nStartPos[i+1]; -BV&u(
} Lh &L5p7
nEndPos[nEndPos.length-1] = nFileLength; ~P5!VNJ;r
} 9tS&$-
} F|V co]"S1
b>%I=H%g
<EI'N0~KG
//启动子线程 zYOPE 6E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )`rC"N)
for(int i=0;i<nStartPos.length;i++) ^;YD3EZw
{ H[x9 7r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -X4`,0y%{O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e7L;{+XI
nStartPos,nEndPos,i); JoZC+G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "`:#sF9S
fileSplitterFetch.start(); 6x@-<{L
} ]dDyz[NuvD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :B- ,*@EU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #G#gB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A|>a Gy
nEndPos = " + nFileLength); xDr *|d
// fileSplitterFetch[nPos.length-1].start(); l}AB):<Z
3F}d,aB A
Iz{AA-
//等待子线程结束 v;K\#uc_
//int count = 0; C-6+ZIk4
//是否结束while循环 NHc+QMbou(
boolean breakWhile = false; Q}2w~Cn\S
db%`-UST
?qK:P
while(!bStop) <1jiU%!w
{ [1vrv(u>
write_nPos(); .Yu,&HR
Utility.sleep(500); Nq~bO_-I
breakWhile = true; 'ZDa*9nkF
9)YG)A~<
rWvJ{-%
for(int i=0;i<nStartPos.length;i++) /|DQ_<*
{ Vk_L*lcN
if(!fileSplitterFetch.bDownOver) YT:5J%"
{ vRY4N{v(<
breakWhile = false; =C:0='a
break; (8ymQ!aY
} pI^n("|
} Lq&xlW j
if(breakWhile) o4Ba l^=[
break; dvj`%?=
_88~uYG
qzyQ2a_p
//count++; 7v:;`6Jb
//if(count>4) *LhR$(F(
// siteStop(); }gn0bCJy
} Sn+Yi
}ps6}_FE
JEd/j zR(
System.err.println("文件下载结束！"); %q!nTGU~
} bIhL!Ty T.
catch(Exception e){e.printStackTrace ();} PQs9@]w[
} f[ywC$en
>pYgF=J
9!OpW:bR|
//获得文件长度 X3>(K1
public long getFileSize() i}YnJ
{ j?,$*Fi
int nFileLength = -1; =wQ=`
try{ _\<M58/z
URL url = new URL(siteInfoBean.getSSiteURL()); BZBsE :(F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dvf*w:5K!
httpConnection.setRequestProperty("User-Agent","NetFox"); 8,=$>@u
Psv!`K
iOyYf!yg
int responseCode=httpConnection.getResponseCode(); 83n: h08
if(responseCode>=400) v$cD!`+k
{ t Z%?vY~!
processErrorCode(responseCode); w*}9;l
return -2; //-2 represent access is error DjKjEZHgM
} 7PMZt$n
t&xx-4
P8jK yo
String sHeader; A_.QHUjpx
8%4`Yj=
sHF vzE%
for(int i=1;;i++) 6~}H3rvO}
{ *t_&im%E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |^F-.Z
//Utility.log(in.readLine()); >4\xcL
sHeader=httpConnection.getHeaderFieldKey(i); u!i5Q
if(sHeader!=null) 5-OvPTY`M
{ >$y >
if(sHeader.equals("Content-Length")) Y8PT`7gd`
{ 9<#D0hh$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q0~_D8e,
break; ;i9CQ0e?
} a5-\=0L~
} :m d3@r']
else fDd!Mt
break; HhL%iy1
} +2SX4Kxu
} L3AwL)I
catch(IOException e){e.printStackTrace ();} `y}d)"!
catch(Exception e){e.printStackTrace ();} i.sq^]j
^aXBt
7mM;Q
Utility.log(nFileLength); =@2V#X]M*
qedGBl&
T Rw6$CR
return nFileLength; Q(UGwd1
} Q$1K{14I
D.(G9H
j;)g+9`
//保存下载信息（文件指针位置） oui!fTy
private void write_nPos() <^U(ya
{ $VWzv4^:
try{ s3{s.55{m
output = new DataOutputStream(new FileOutputStream(tmpFile)); #ja`+w}
output.writeInt(nStartPos.length); (L$~zw5gr
for(int i=0;i<nStartPos.length;i++) ?Z>.G{Wm@
{ U*Qq5=dqD
// output.writeLong(nPos); aLi_Hrb9
output.writeLong(fileSplitterFetch.nStartPos); f_ztnRw
output.writeLong(fileSplitterFetch.nEndPos); (0W}e(D8
} vo(NB !x$
output.close(); s&hA
} ,g_onfY
catch(IOException e){e.printStackTrace ();} d&uTiH?0
catch(Exception e){e.printStackTrace ();} | ",[C3Jg
} Wk\@n+Q{]
)7GLS\uf<%
1~DD9z
//读取保存的下载信息（文件指针位置） i ,pN1_-
private void read_nPos() UMuuf6
{ UZP6x2:=
try{ cEc,eq|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U}w+`ZLN
int nCount = input.readInt(); K;p<f{PE
nStartPos = new long[nCount]; >:E*7
nEndPos = new long[nCount]; QZ3(u<f
for(int i=0;i<nStartPos.length;i++) ~59`S#ax/l
{ 0^_lj9B!
nStartPos = input.readLong(); yW^IN8fm
nEndPos = input.readLong(); ^qO=~U!{
} & 8'(
input.close(); \c~{o+UD-
} ]1d,O^S
catch(IOException e){e.printStackTrace ();} 96pk[5lj{?
catch(Exception e){e.printStackTrace ();} x8?x/xE
} 0[:9 Hb6
f{Fe+iPc
-,Q$
private void processErrorCode(int nErrorCode) J+b!6t}mZn
{ 5m^Hi}S_
System.err.println("Error Code : " + nErrorCode); Q_aqX(ig
} Ji6`-~ k
j\'+wVyo
FU\/JF.j
//停止文件下载 zD2.Q%`IM
public void siteStop() -/UXd4S
{ px_s@>l`
bStop = true; e" Eqi-
for(int i=0;i<nStartPos.length;i++) 8jggc#.
fileSplitterFetch.splitterStop(); .vN%UNu
.6#cDrK
lMBX!9z
} ^p 2.UW
} >X[|c"l.
//负责部分文件的抓取 )d}H>Qx=
**FileSplitterFetch.java _k_>aG23
*/ j?\$G.Y
package NetFox; mA(nyF
x*me'?q
'7Mep ]
import java.io.*; UU iNR
import java.net.*; K/vxzHSl
1mHwYT+
{gFAvMj#
public class FileSplitterFetch extends Thread { nTys4R
s~=KhP~
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String sURL; //File URL nW|'l^&
long nStartPos; //File Snippet Start Position 5/B#)gm
long nEndPos; //File Snippet End Position ^W Y8-6
int nThreadID; //Thread's ID WI1T?.Gc
boolean bDownOver = false; //Downing is over + a-wv
boolean bStop = false; //Stop identical R=-+YBw7/
FileAccessI fileAccessI = null; //File Access interface .E+OmJwD
(U|)xA]y!
C=N!z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w4\BD&7V
{ Hf VHI1f
this.sURL = sURL; <7=&DpjI7F
this.nStartPos = nStart; EjWgaV
this.nEndPos = nEnd; h&lyxYZ+T$
nThreadID = id; .#*D!;f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $hh+0hs
} r5o@+"!
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public void run() -i#J[>=w{C
{ ;0IvF#SJ(.
while(nStartPos < nEndPos && !bStop) 'gCJ[ce
{ SOVjEo4'3
?TDvCL
yahAD.Xuo@
try{ E W`W~h[
URL url = new URL(sURL); $=/rGpAk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G.E[6G3
httpConnection.setRequestProperty("User-Agent","NetFox"); ^f9>l;Lb
String sProperty = "bytes="+nStartPos+"-"; vX ?aB!nkw
httpConnection.setRequestProperty("RANGE",sProperty); %NNj9Bl<VV
Utility.log(sProperty); Q|?'(J+
sa*g
Hb+X}7c$
InputStream input = httpConnection.getInputStream(); !x>,N%~
//logResponseHead(httpConnection); Oukd_Ryf
kVd5,Qd
I!P4(3skAB
byte[] b = new byte[1024]; /hL\,x2
int nRead; S_6g~PHsr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n+2%tW
{ F>*{e
nStartPos += fileAccessI.write(b,0,nRead); OVZP x%a
//if(nThreadID == 1) C0QM#"[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gljo;f:
} &=X.*H%
eTT)P
=_l)gx+Y+y
Utility.log("Thread " + nThreadID + " is over!"); ZWS2q4/S
bDownOver = true; /2xSNalC
//nPos = fileAccessI.write (b,0,nRead); wjrG7*_Y4v
} /&r|ec5
catch(Exception e){e.printStackTrace ();} +y/55VLq
} /N6}*0Ru
} L_Q S0_1
rh66_eV
k2r3dO@q
//打印回应的头信息 7VAJJv3
public void logResponseHead(HttpURLConnection con) d1c0l{JV3
{ D/CIA8h3
for(int i=1;;i++) Od##U6e`
{ QTH7grB2v
String header=con.getHeaderFieldKey(i); 2z\e\I
if(header!=null) ?2 f_aY ;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^AL2H'
Utility.log(header+" : "+con.getHeaderField(header)); cG{L jt
else O6X"RsI}
break; v+xB7w
} MjD75hIZ
} cE\>f8 I
,6{iT,~@8
F9a^ED0l\
public void splitterStop() 02=lsV!U
{ @1:0h9%
bStop = true; sOpep
} vUesV%9hq
~b)74M/
q%i-`S]}qL
} b~w=v_[(I
E\U`2{^.
,|h)bg7.
/* k|xtr&1N.!
**FileAccess.java g[[;w*;z
*//文件访问(定位，写) .iHn5SGA
package NetFox; yZkyC'/
import java.io.*; k{I01
1P(&J
&(N+.T5cp
public class FileAccessI implements Serializable{ = ieag7!
$I9qgDJ)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5jxQW ;
RandomAccessFile oSavedFile; Y>+y(ck
long nPos; vVl; |
kwpK1R4zs
L+}n@B
public FileAccessI() throws IOException T~_/Vi
{ /X'(3'a
this("",0); s?R2B)a
} sarq`%zrk
{gbn/{
,#?uJTLH
public FileAccessI(String sName,long nPos) throws IOException \p{5D`HY
{ %ru;;h
oSavedFile = new RandomAccessFile(sName,"rw"); Q6'x\
this.nPos = nPos; -#!x|ne
oSavedFile.seek(nPos); qt%D'
} RPd}Wf
l>*"mh
%wcSM~w
public synchronized int write(byte[] b,int nStart,int nLen) } :=Tm]S
{ s,k
int n = -1; 4lhw3,5
try{ Tm_B^W}
oSavedFile.write(b,nStart,nLen); om?-WJI
n = nLen; HK|ynBAo
} )XcOl7XLN
catch(IOException e) Q'_z<V
{ [(1c<b2r
e.printStackTrace (); !*6CWV0
} J+d1&Tw&
/|6;Z}2
T^J>ZDA
return n; E4m`
} C4TE-OM8
$!&*xrrNM
Reatdh
} Jgnhn>dHe
RV@*c4KvO+
^%O]P`$
/* OS8q( 2z?s
**SiteInfoBean.java o=0]el^A
*/ E[Cb|E
package NetFox; tHzZ@72B7
Q7W>qe%4
"etPT@gF
public class SiteInfoBean { w^t/9Nasi
XQw>EZdj_N
lok=
private String sSiteURL; //Site's URL n=[/Z!
private String sFilePath; //Saved File's Path 9-MUX^?u
private String sFileName; //Saved File's Name JH7<
private int nSplitter; //Count of Splited Downloading File o}ZdTf=
8@tV9+u
%n*-VAfE\
public SiteInfoBean() x&0vKo;
{//nSplitter的缺省值为5 fk&8]tK4
//default value of nSplitter is 5 .0es3Rj
this("","","",5); WYr/oRO
} <)3u6Vky9
9g<7i
T:; 2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jbAx;Xt'=M
{ /HaHH.e
sSiteURL= sURL; ,k;^G>< =
sFilePath = sPath; !_Wi!Vr_
sFileName = sName; sfNE68I2
this.nSplitter = nSpiltter; n^g|Ja
maNl^i
U[ 0=L`0e
} #~ )IJ
xsD($_
s6@DGSJ
public String getSSiteURL() |EJD3&
{ B&n<M]7
return sSiteURL; XzEc2)0'v
} N u<_}
QD0"rxZJ
N(Fp0
public void setSSiteURL(String value) UdpF@Q
{ q!|*oUW
sSiteURL = value; A\HxDIU
} ;6>2"{NW
(pv+c,
sTn<#l6
public String getSFilePath() rustMs2p
{ tp63@L|Q
return sFilePath; +%ee8|\
} xdp`<POn%
JvVWG'Z"
iOW#>66d
public void setSFilePath(String value) i3@)W4{
{ X\{LnZ@r4
sFilePath = value; Vex{.Vh,"
} "@iK' c^
>7jbgHB
,$s8GAmq
public String getSFileName() VY |_dk
{ `d5%.N
return sFileName; Ya3C#=
} +BETF;0D
\Q0[?k
aX)I3^ar
public void setSFileName(String value) Yc_8r+;(
{ WW4vn|0v
sFileName = value; .F
} ,|y:" s
1OCeN%4]Qk
MQ5R O;RY
public int getNSplitter() z> Rsi
{ 0D\#Pq v
return nSplitter; $rv8K j+
} !t$'AoVBq
v$7QIl_/7
$q6BP'7
public void setNSplitter(int nCount) Ugu[|,
{ uki#/GzaO
nSplitter = nCount; Rdvk ml@@
} DS+}UO
} n0r+A^]
~$Tkn_w#
{> eXR?s/
/* `q}I"iS
**Utility.java ALrw\qV
*/ "-e \p lKj
package NetFox; =mS\i663
@e(o129
nzd2zY>V
public class Utility { ~ELNyI11
(D#B_`;-
diJLZikk
public Utility() hL/)|N~
{ t2/#&J]
Isvx7$Vu+
kpJ@M%46
} *7CV^mDm
K&vF0*gN3
//线程睡眠 CJ1 7n
public static void sleep(int nSecond) h].<t&
{ wW7eT~w
try{ xbdN0MAU
Thread.sleep(nSecond); {@eJtF+2
} `IP/d
catch(Exception e) $+P>~X)
{ }SX,^|eN
e.printStackTrace (); 5:pM4J
} 3,p]/Z_
} "fG8?)d;
uD\?(LM
//日志 <Wfx+F
public static void log(String sMsg) &M46&^Jho
{ }Ga\wV
System.err.println(sMsg); oC<.=2]
} `bFff%_
kh {p%<r{
7op`s5i
public static void log(int sMsg) #bUXgn>
{ d:#yEC
System.err.println(sMsg); igkYX!0#8O
} s%qF/70'
} C>-aIz!y
Lhl]g^SN
w$+&3t
/* /j4P9y^]=
**TestMethod.java Y'1S`.
*/ +1uF !G&l
package NetFox; KV}FZ3jY
qs1 ?IYD
4A8;tU$&
public class TestMethod { [0(B>a3J
N/Z2hn/m
YUx.BZf7
public TestMethod() ruc++@J@
{ ///xx/weblogic60b2_win.exe xAK6pDp
try{ !j:9`XD|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "Om=N@?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @aAW*D~-J
SiteFileFetch fileFetch = new SiteFileFetch(bean); |%J{RA
fileFetch.start(); -7*ET3NSI/
} v/](yT
catch(Exception e){e.printStackTrace ();} =7w\ 7-.m
9Xj7~,
K@sV\"U(*E
} ,24p%KJ*X
}@;ep&b*
UELy"z R
public static void main(String[] args) 'JCZ]pZ
{ VXYK?Qc'
new TestMethod(); S& SQ
} OHeT,@(mh
} j<Bkj/
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