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)); L>NL:68yN
} 9r<J"%*Q
for(int i=0;i<nEndPos.length-1;i++) "]x'PI 4J
{ 5iw<>9X*
nEndPos = nStartPos[i+1]; fLD,5SN
} ~i{(<.he
nEndPos[nEndPos.length-1] = nFileLength; >d*@_kJM
} !bx;Ta.
} )Y0!~# `
(ejvF):|
&|ex`nwc0
//启动子线程 rgv?gaQ>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l -mfFN
for(int i=0;i<nStartPos.length;i++) w"|L:8
{ 1..+F0U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a=1@*ID
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8.=BaNU
nStartPos,nEndPos,i); =.U[$~3q%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q=m'^ ,gPS
fileSplitterFetch.start(); <CiSK!
} ]t,BMu=%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O`\;e>!t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @6sqMw}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |\t-g"~sN
nEndPos = " + nFileLength); 7~p@0)''
// fileSplitterFetch[nPos.length-1].start(); [`[|l
uEP*iPLD@
"ycJ:Xv49
//等待子线程结束 2r4Uh1D~
//int count = 0; 6=/F$|
//是否结束while循环 mb3"U"ohs
boolean breakWhile = false; |4zIfAO
cn3\kT*
su(1<S}
while(!bStop) rJTa
{ F6|]4H.3Q
write_nPos(); RVmh6m
Utility.sleep(500); [Ek7b*
breakWhile = true; o5GcpbZ3k
(@VMH !3
LEf^cM=>
for(int i=0;i<nStartPos.length;i++) D%SlAzZ3
{ ]Sz:|%JP1
if(!fileSplitterFetch.bDownOver) uym*a4J
{ H;LViP2K*
breakWhile = false; @ioJ]$o7
break; rfJz8uF%
} |F[+k e
} ]^7@}Ce_
if(breakWhile) }?i0 I
break; 5m 4P\y^a
UnV.~u~
OLGE!&!>
//count++; P>D)7V9Hh
//if(count>4) qgHWUwr+n
// siteStop(); sb*G!8j
} "m8^zg hL
aFm_;\
p)-^;=<B3
System.err.println("文件下载结束！"); M"Hf :9Rk
} 6;d*r$0Fc
catch(Exception e){e.printStackTrace ();} v{N`.~,^
} R+z2}}Z!`
F~W6Bp^W
1n8/r}q'H
//获得文件长度 @*XV`_!h
public long getFileSize() xm~`7~nFR
{ 4E+e}\r:6
int nFileLength = -1; bsli0FJSh'
try{ V)k4:H
URL url = new URL(siteInfoBean.getSSiteURL()); pYEMmZ?L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |syR6(U}
httpConnection.setRequestProperty("User-Agent","NetFox"); .`H5cuF`
lrE5^;/s1
8/#A!Ww]
int responseCode=httpConnection.getResponseCode(); Pmx-8w
if(responseCode>=400) I$G['`XX/
{ gz9j&W.
processErrorCode(responseCode); JPHL#sKyz
return -2; //-2 represent access is error +3BN}
} J*A,o~U|
|YWD8 +
C.-,^+t;g
String sHeader; [|$h*YK
VCkq"f7cw
n( yn<
for(int i=1;;i++) Ll't>)
{ YkSl^j[DHs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +Kc
//Utility.log(in.readLine()); &r/Mi%
sHeader=httpConnection.getHeaderFieldKey(i); $%d*@'c
if(sHeader!=null) V f&zL Sgr
{ FD #8mg
if(sHeader.equals("Content-Length")) O0v}43J[
{ F/{!tx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b8t7u
break; Sz`,X0a
} RtS+<^2a;
} ? OM!+O
else 1CZgb
break; T7%S #0,p
} H*R"ntI?w
} hn@08t G
catch(IOException e){e.printStackTrace ();} K69'6?#
catch(Exception e){e.printStackTrace ();} (?c"$|^J
kDioD
bAqA1y3=
Utility.log(nFileLength); p]TAELy
2%m BK
2/^3WY1U
return nFileLength; </zEg3F\
} C,r;VyW6BI
*i%d,w0+
~36!?&eA8
//保存下载信息（文件指针位置） d7upz]K9g
private void write_nPos() q|(HsLs
{ g!|kp?
try{ ;6$jf:2m
output = new DataOutputStream(new FileOutputStream(tmpFile)); KZE,bi:~
output.writeInt(nStartPos.length); rb.N~
for(int i=0;i<nStartPos.length;i++) n_A3#d<9
{ vk^xT
// output.writeLong(nPos); n7[V&`e_
output.writeLong(fileSplitterFetch.nStartPos); 1Pu~X \sO
output.writeLong(fileSplitterFetch.nEndPos); lL3U8}vn
} *g2x%aZWbG
output.close(); Jnov<+
} d$!RZHo10V
catch(IOException e){e.printStackTrace ();} {EQOP]
catch(Exception e){e.printStackTrace ();} g) jYFfGfH
} ~$^XP.a.
}Sv:`9=
T0)@pt7>
//读取保存的下载信息（文件指针位置） DTL.Bsc-.
private void read_nPos() ~f98#43
{ aW7^d'ZZ\
try{ 8l`*]1.W<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f]CXu3w(J
int nCount = input.readInt(); h:|qC`}
nStartPos = new long[nCount]; wmLs/:~
nEndPos = new long[nCount]; %h!B^{0
for(int i=0;i<nStartPos.length;i++) sO@Tf\d
{ zrb}_
nStartPos = input.readLong(); Q![@c
nEndPos = input.readLong(); 8d'0N
} (jE9XxQY
input.close(); 6i/(5 nQ
} 26h21Z16q
catch(IOException e){e.printStackTrace ();} b]KBgZ
catch(Exception e){e.printStackTrace ();} R\[e!g*I
} ~4'$yWG
FZnw0tMq
3!]rmZ-W
private void processErrorCode(int nErrorCode) (GfZ*
{ '`Hr}
System.err.println("Error Code : " + nErrorCode); Dlvz)
} ;4\;mmLVk
\9T7A&
<e6#lFQqK
//停止文件下载 j3Y['xDv
public void siteStop() 0g8NHkM:2a
{ 3JR+O<3D
bStop = true; +ZP7{%
for(int i=0;i<nStartPos.length;i++) 5{,<j\#L
fileSplitterFetch.splitterStop(); ef4 i:.
$I?"lky
$XH^~i;
} /)O"l@ }U
} ]`WJOx4
//负责部分文件的抓取 z F;K
**FileSplitterFetch.java ?S=mybp
*/ 4*;MJ[|
package NetFox; seJ^s@H5l
JucY[`|JV
jPkn[W# 6
import java.io.*; hDGF7
import java.net.*; Wd ELV3
Z;"vW!%d
veECfR;
public class FileSplitterFetch extends Thread { 9>#6*/Oa7
[Ch.cE_
M',?u
String sURL; //File URL klhtKp_p
long nStartPos; //File Snippet Start Position F:DrX_O%
long nEndPos; //File Snippet End Position _)-o1`*-
int nThreadID; //Thread's ID \fe]c :
boolean bDownOver = false; //Downing is over q5S9C%b
boolean bStop = false; //Stop identical dAj$1Ke
FileAccessI fileAccessI = null; //File Access interface ]]yO1x$Kk
Dvln/SBk
c:.eGH_f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V(*(F7+
{ g9F?z2^
this.sURL = sURL; ddR>7d}N
this.nStartPos = nStart; ybUaTD@?}b
this.nEndPos = nEnd; e96k{C`j0
nThreadID = id; ^<AwG=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x,Vr=FB
} hpk7 Anp
RG`1en
=g|FT
public void run() =tY T8Q;al
{ |Q>IrT
while(nStartPos < nEndPos && !bStop) 9&NgtZpt
{ >LuYHr
#_lDss
e>7i_4(C
try{ 4KrL{Z+}
URL url = new URL(sURL); T6k0>[3xf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3+bt~J0
httpConnection.setRequestProperty("User-Agent","NetFox"); D1;QC
String sProperty = "bytes="+nStartPos+"-"; <9 ;!3xG
httpConnection.setRequestProperty("RANGE",sProperty); {l>hMxij
Utility.log(sProperty); jZ; =so
E4xa[iZ
qIqM{#' ^
InputStream input = httpConnection.getInputStream(); a.6(K
//logResponseHead(httpConnection); @=kSo -SX
lw5`p,`
n'w.; q
byte[] b = new byte[1024]; PFK '$
int nRead; n(]-y@X0_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;*&-C9b
{ Yz<1 wt7;
nStartPos += fileAccessI.write(b,0,nRead); @s^-.z
//if(nThreadID == 1) RpYERAgT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7VI*N)OZ8
} " 2Dngw
FxtI"g\0
POR\e|hRT]
Utility.log("Thread " + nThreadID + " is over!"); VLN_w$iEq
bDownOver = true; !{41!O,K#
//nPos = fileAccessI.write (b,0,nRead); G*v,GR
} ?0xgRe<
catch(Exception e){e.printStackTrace ();} &jr3B;g!C
} KY]C6kh
} N,U8YO
;jTN| i'
7"xd1l?zz
//打印回应的头信息 6S\8$
public void logResponseHead(HttpURLConnection con) Y[S1$(K&*
{ >@AB<$A
for(int i=1;;i++) RCLeA=/N@0
{ C{wEzM:
String header=con.getHeaderFieldKey(i); M& CqSd
if(header!=null) \5cpFj5%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n{SJ_S#a.a
Utility.log(header+" : "+con.getHeaderField(header)); A.w:h;7
else vVcob}ZH
break; ei5~&
} 4nz35BLr
} z&^&K}
k-""_WJ~^
C"]^Q)aJN
public void splitterStop() sUm'
{ *4_Bd=5(U
bStop = true; Nl1Do:PY
} 9Lfv^V0
:P=(k2
G9@0@2aY8
} wn)W ?P;k
<_KIK
{cw /!B
/* 5i{j' {_(8
**FileAccess.java eQvg7aO;
*//文件访问(定位，写) O%HHYV%[m
package NetFox; Jqi%|,/]N
import java.io.*; ##4HYQ%E
0'o:#-
1ZB"EQ
public class FileAccessI implements Serializable{ m<2M4u
GNJj=1Lsd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W'u>#
RandomAccessFile oSavedFile; mUx+Y]Ep
long nPos; xFg>SJ7]
iMRwp+$
26x[X.C:
public FileAccessI() throws IOException Nu~lsWyRI5
{ 8|58 H
this("",0); YkQd
} eO[b1]WLP
*bpD`s @
6/dI6C!
public FileAccessI(String sName,long nPos) throws IOException KdbHyg<4
{ @49S`
oSavedFile = new RandomAccessFile(sName,"rw"); !m?-!:
this.nPos = nPos; d9|<@A
oSavedFile.seek(nPos); 3|Xyl`i4o
} tcog'nAz
}?v )N).kW
LvYB7<zk>
public synchronized int write(byte[] b,int nStart,int nLen) _``=cc
{ >t_6B~x9
int n = -1; ?=fyc1
try{ F`]2O:[
oSavedFile.write(b,nStart,nLen); WQO) =n
n = nLen; G9<X_
} /fV;^=:8c
catch(IOException e) ?#UO./"
{ OprkR
e.printStackTrace (); OY@ %p}l
} vd4ytC
PXNh&N
WVvvI9
return n; (7=9++uU
} {h`uV/5@`
>`ZyG5
| (_
} HT1!5
A1zjPG&]
Bo%NFB;
/* ]~hk6kS8Q
**SiteInfoBean.java !0mI;~q|F
*/ U}j0D2
package NetFox; 'F#KM1s
B~Xw[q
mUF,@>o
public class SiteInfoBean { p0<\G
<B8!.|19
/FEVmH?
private String sSiteURL; //Site's URL L8#5*8W6
private String sFilePath; //Saved File's Path !f&g-V
private String sFileName; //Saved File's Name @/-\k*T
private int nSplitter; //Count of Splited Downloading File G{%LB}2
fNZ__gO!%
t |A-9^t'!
public SiteInfoBean() (0y~%J
{//nSplitter的缺省值为5 WlBc.kFck
//default value of nSplitter is 5 R`^_(yn>
this("","","",5); hSyql
} Otm0(+YB7
:1KpGj*F
t" Z6[XG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H\tUpan6fy
{ 3y8G?LL/[7
sSiteURL= sURL; 03S]8l
sFilePath = sPath; /{--+ C
sFileName = sName; +pn N!:q
this.nSplitter = nSpiltter; {8,J@9NU
AoL2@C.C%D
n3 r3"~i
} ThbGQ"/
|R\>@Mg#B
R2]Z kg
public String getSSiteURL() rK]Cr9WM
{ >{J(>B\
return sSiteURL; Ur=(.%@
} ' x35=@
74k dsgQf
!fR3(=oN
public void setSSiteURL(String value) !AfHk|
{ 3c6b6
sSiteURL = value; 0-yp,G
} mahJSz(3
9=h'9Wo
@x'"~"%7b
public String getSFilePath() ^mO~W!"
{ 8jo p_PG'
return sFilePath; iq( E'`d
} E3gh?6
)@Yf]qx+Y<
n'kG] Q
public void setSFilePath(String value) Rww{:R
{ W~9tKT4
sFilePath = value; -0{r>,&Mm
} .|b$NM
# ,_u_'C*!
"x*egI
public String getSFileName() :hFIl0$,"3
{ Mh/dpb\Z
return sFileName; cacr=iX
} X4Ic;
,J^b0@S
"(z5{z?S
public void setSFileName(String value) mA+&Io
{ %9N7Ln|%
sFileName = value; v>Yb/{A
} vK\%%H
6qoyiT%P&
[] `&vWZ
public int getNSplitter() _'>oXQJ
{ ``Dq
return nSplitter; vAh6+K.e
} ,3p~w5C/+[
BJsz2t :0
W;L7SF g)
public void setNSplitter(int nCount) C|).;V&
{ 1&)?JZhg
nSplitter = nCount; nvJf/90$
} ]?+p5;{y4
} !K}~/9Z=m
(ehK?6[
`W:%mJd9
/* ?:8ido#-
**Utility.java +*T7@1
*/ Dhw(#{N
package NetFox; UU mTOJr
2w_WAdi
8I8 F/47x
public class Utility { $.PuK~}
'y2nN=CN
PQnF
public Utility() /VS[pXXT|
{ m~P CB_ifW
V4P; 5[
NI#:|}CYS
} ,5kKimTt
7;sj%U^'l
//线程睡眠 bRJMYs
public static void sleep(int nSecond) W<$Z=(_v
{ Iw&vTU=2
try{ {fF3/tL
Thread.sleep(nSecond); k*E\B@W>
} )- viGxJ@
catch(Exception e) 36%nB*
{ xtE_=5$~
e.printStackTrace (); !?p%xj?
} 6c"0})p
} +5o8KYV
=Z+nz^'b
//日志 $8xl#SqH
public static void log(String sMsg) ') gi%
{ o/6-3QUak
System.err.println(sMsg); V\6[}J
} ^G.Xc\^w:
QM O!v;
QP)pgAc
public static void log(int sMsg) %Nhx;{
{ ,TPISs
System.err.println(sMsg); g[Ib,la_a
} ang~<
} Xr2ou5zAn
.DR<Te
%K`% *D
/* Y/ee~^YxK'
**TestMethod.java `m?c;,\
*/ qT"Q1xU[
package NetFox; Bck7\
m~Bl*`~M
R_68-WO
public class TestMethod { wX[8A/JPD
)V ;mwT!Q
MHai%E
public TestMethod() n\5RAIg
{ ///xx/weblogic60b2_win.exe r77PQQDT
try{ 'u_t<F]b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ->O2I?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #hf ak
SiteFileFetch fileFetch = new SiteFileFetch(bean); \2}bi:e6
fileFetch.start(); te !S09(
} <]4i`6{v
catch(Exception e){e.printStackTrace ();} ;F#7Px(q
?)[EO(D
%1O[i4s:-
} H5]^ 6 HwX
2eC(Ijq[a
!V\Q<So<
public static void main(String[] args) T G{k0cdOT
{ t{FlB!jv
new TestMethod(); Yd=a}T
} 9^Whg~{
} >teOm?@U
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