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)); cgz'6q'T
} A]H+rxg
for(int i=0;i<nEndPos.length-1;i++) ^<y$+HcH
{ < "~k8:=4
nEndPos = nStartPos[i+1]; ~-W.yg6D{
} PU-~7h+$
nEndPos[nEndPos.length-1] = nFileLength; l_,8_u7G
} P92:}" )*>
} g^0
)s6tjlf8
;P2~cQjD;
//启动子线程 f_Wn[I{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !^8'LMY<I
for(int i=0;i<nStartPos.length;i++) #e8CuS
{ K[?wP>s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?[m5|ty#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Llk`
nStartPos,nEndPos,i); HnY: gu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3_33@MM
fileSplitterFetch.start(); ^xqh!
} c#Y9L+O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u{H_q&1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pyyx/u+?@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", brTB /(E
nEndPos = " + nFileLength); )9<)mV*EB(
// fileSplitterFetch[nPos.length-1].start(); "UAW
X(WG:FP27
6?,r d
//等待子线程结束 Z>M*!mQi
//int count = 0; q5HHMHB
//是否结束while循环 OmoY] 8N}
boolean breakWhile = false; Mm/GIa
[,1j(s`N5
K} ;uH,
while(!bStop) ait/|a
{ QkF-}P%
write_nPos(); 0f-gQD
Utility.sleep(500); E* lqCh
breakWhile = true; @l;f';+
/1OhW>W3eH
c69C=WQ
for(int i=0;i<nStartPos.length;i++) ~z< ? Wh
{ ]\_4r)cN<n
if(!fileSplitterFetch.bDownOver) .0a$E`V=D
{ DH9?~|
breakWhile = false; KRXe\Sx
break; Q7DkhKT
} fqF1-%
} Y:byb68
if(breakWhile) |20p#]0E+
break; LXK+WB/s
9k*'5(D4S
PMTyiwlm
//count++; UhEnW8^bz1
//if(count>4) E4{^[=}
// siteStop(); W0nRUAo[
} BRW
FijzO
] xH `
System.err.println("文件下载结束！"); L^0jyp
} SgY>$gP9S
catch(Exception e){e.printStackTrace ();} JgxOxZS`@
} IGbQ L
!D6@\
HZP`u >.
//获得文件长度 0#yo\McZ
public long getFileSize() ~Aq UT]l
{ 35,SPR
int nFileLength = -1; a]ftE\99
try{ bF}~9WEa
URL url = new URL(siteInfoBean.getSSiteURL()); `U;4O)`n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ( E0be.
httpConnection.setRequestProperty("User-Agent","NetFox"); \?GMtM,
0<P -`|X
R"82=">v
int responseCode=httpConnection.getResponseCode(); RQh4RUm
if(responseCode>=400) icnp^2P
{ A46y?"]/30
processErrorCode(responseCode); k|g~xmI;
return -2; //-2 represent access is error IPY@9+]
} M<)HJ lr
#nu?b?X'
fYH%vr)
String sHeader; fo5!d@Nv
ikofJl]9
jmAWto}.
for(int i=1;;i++) ?5+=
{ J[<:-$E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \Mi y+<8$
//Utility.log(in.readLine()); 9 s>JdAw?
sHeader=httpConnection.getHeaderFieldKey(i); K\;b3
if(sHeader!=null) IJs`3?
{ 0_%u(?
if(sHeader.equals("Content-Length")) BGUP-_&
{ 8WaVs6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T"dEa-O
break; paiF ah
} km8[azB o
} rt."P20T
else Z!ub`coV[
break; 0h#' 3z<
} ,H.q%!{h_
} q5QYp
catch(IOException e){e.printStackTrace ();} P+oZS
catch(Exception e){e.printStackTrace ();} v_oNM5w
#Ok*Or
*xt3mv/<z
Utility.log(nFileLength); EY&hWl*a^
W**a\[~$
&%INfl>o7.
return nFileLength; G#K=n
} x==%BBnO%
a[t2TjB
~KCOCtiD
//保存下载信息（文件指针位置） ku?i[Th
private void write_nPos() i"zWv@1z
{ p5Y"W(5_
try{ 3VKArv-
output = new DataOutputStream(new FileOutputStream(tmpFile)); `F(KM '
output.writeInt(nStartPos.length); ^ b}_[B
for(int i=0;i<nStartPos.length;i++) qL3*H\9N
{ jYuH zf
// output.writeLong(nPos); &grT}
output.writeLong(fileSplitterFetch.nStartPos); H{9di\xnEm
output.writeLong(fileSplitterFetch.nEndPos); ^TnBtIU-B
} {aAA4.j^
output.close(); !7Ta Vx}`(
} ~u-mEdu3C
catch(IOException e){e.printStackTrace ();} R`A@F2
catch(Exception e){e.printStackTrace ();} Uln[UK
} rHh<_5-/>
llI`"a
`2UzJ~
//读取保存的下载信息（文件指针位置） .3!=]=
private void read_nPos() a B%DIH,
{ $I+QyKO9k
try{ mZ*!$P:vy"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t&0pE(MO/
int nCount = input.readInt(); mmEr2\L
nStartPos = new long[nCount]; Qnph?t>
nEndPos = new long[nCount]; [,$] %|6wt
for(int i=0;i<nStartPos.length;i++) b6Dve]
{ kW5g]Q
nStartPos = input.readLong(); =A04E
nEndPos = input.readLong(); [v#t
} $^}?98m
input.close(); }"%tlU!}
} i,Yv
catch(IOException e){e.printStackTrace ();} quVTqhg"
catch(Exception e){e.printStackTrace ();} b=`h""u
} xR\$2(
27G6C`}
TU7Qt<
private void processErrorCode(int nErrorCode) LEWeybT
{ 8`kK)iCq
System.err.println("Error Code : " + nErrorCode); CR&v z3\Q
} -dZ7;n5&_
0vt?yD
`/8Dmg
//停止文件下载 %fo+Y+t
public void siteStop() U,~\}$<I
{ gI<TfcC
bStop = true; $9j\sZj&
for(int i=0;i<nStartPos.length;i++) $62!R]C9\
fileSplitterFetch.splitterStop(); &}Cm9V
(n|PLi
(%YFcE)SRS
} M)#aX|%Mh
} a9`E&Q}z
//负责部分文件的抓取 v&D^N9hy9
**FileSplitterFetch.java tc.R(F96
*/ 5ZSV)$t
package NetFox; u-$(TyDEl|
I!|_C~I`2
S{7A3 x'B
import java.io.*; ZM`6zS!
import java.net.*; NDWpV
v&;q4b4
,dLh`t<\
public class FileSplitterFetch extends Thread { %!mJnc%
NVAt-u0LB
yL7D;<!S&
String sURL; //File URL u`O xY
long nStartPos; //File Snippet Start Position P=OHiG\z
long nEndPos; //File Snippet End Position DKx8<yEky
int nThreadID; //Thread's ID 4 >at#Zc
boolean bDownOver = false; //Downing is over yF0\$%H>$
boolean bStop = false; //Stop identical T6*naH
FileAccessI fileAccessI = null; //File Access interface (i^{\zv
4siNY4i"
gu7mGHn-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pQKR
{ #HfvY}[o
this.sURL = sURL; z:{'IY
this.nStartPos = nStart; ?suNA
this.nEndPos = nEnd; g[!t@K
nThreadID = id; w$MFCJ:p&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %O#)=M~
} YIvJN
oJA%t-&%R
PbvRh~n
public void run() J=JYf_=4bc
{ ~Pq1@N>n
while(nStartPos < nEndPos && !bStop) FctqE/>}I
{ oi^2Pvauh
33z)F
^1sX22k
try{ lTBPq?4{
URL url = new URL(sURL); r({!ejT{U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PGF=q|j9K
httpConnection.setRequestProperty("User-Agent","NetFox"); *7u~`
String sProperty = "bytes="+nStartPos+"-"; O0`sg90,C
httpConnection.setRequestProperty("RANGE",sProperty); rlEEf/m:
Utility.log(sProperty); OXd617
B2w\
-!f)P=S
InputStream input = httpConnection.getInputStream(); "l&=a1l
//logResponseHead(httpConnection); "7mYs)=
~za=yZo7(
GVP"~I~/:
byte[] b = new byte[1024]; ]r8t^bqe
int nRead; pC2ZN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N}HQvlLkF9
{ $w4%JBZr
nStartPos += fileAccessI.write(b,0,nRead); Cp` [0v~0
//if(nThreadID == 1) Vf9PHHH|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %5Hsd
} \ 'G%%%;4
N3nFE:`u]
^x-vOGlR
Utility.log("Thread " + nThreadID + " is over!"); uu@Y]0-
bDownOver = true; B8;jRY
//nPos = fileAccessI.write (b,0,nRead); PY- 1 oP
} /n;Ll](ri
catch(Exception e){e.printStackTrace ();} :34]}`-
} `?r]OVe{y
} S{'/=Px+
#}*w &y
|h$*z9bsf
//打印回应的头信息 KE!aa&g
public void logResponseHead(HttpURLConnection con) `@1y|j:m
{ lO3W:,3_a
for(int i=1;;i++) dfl| 6R
{ S<HR6Xw
String header=con.getHeaderFieldKey(i); o=@0Bd8
if(header!=null) d$Y3 a^O|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t\Pn67t
Utility.log(header+" : "+con.getHeaderField(header)); nm5zX,
else VOr*YB&
break; |U)m'W-(q
} d*Q:[RUf,
} 8s(?zK\
hqrI%%
+EK(r@eV
public void splitterStop() 5{/CqUIl
{ XHU&ix{Od
bStop = true; uTgBnv(Y*
} _yk} [x0>
M0VC-\W7f
xEdCGwgp#
} `7_=2C
DID&fj9m
swNJ\m
/* pie<jZt
**FileAccess.java *qdf?'R
*//文件访问(定位，写) hd{Vz{;W
package NetFox; jm9J-%?
import java.io.*; ]AkHNgW
]4~- z3=y
2ED^uc: 0S
public class FileAccessI implements Serializable{ ?g9mDe;k
E)z[@Np
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JA0$Fz
RandomAccessFile oSavedFile; m| 8%%E}d
long nPos; $Gt1T[:QUX
D>"U0*h
*I,3,zO
public FileAccessI() throws IOException 8&snLOU -Q
{ E/ %S0
this("",0); tk3%0XZH
} 6&V4W"k
\;AW/&Ea
~um+r],@@
public FileAccessI(String sName,long nPos) throws IOException ;m6Mm`[i<
{ BkfWZ O{7
oSavedFile = new RandomAccessFile(sName,"rw"); 3?|gBiX
this.nPos = nPos; gNkx]bm
oSavedFile.seek(nPos); Y^5X>
} obWBX'
dv3+x\`9
[ox!MQ+s
public synchronized int write(byte[] b,int nStart,int nLen) r"#h6lYK&
{ 5<Mht6"H
int n = -1; _\yrR.HIa
try{ h $)thW
oSavedFile.write(b,nStart,nLen); LX A1rgUWT
n = nLen; yH_L<n
} N!" ]e*q
catch(IOException e) :()(P9?
{ pcw!e_"+
e.printStackTrace (); 86d*
} |rJ_
%4QCUc*lr
dLOUL9hf
return n; N{Og; roGD
} - bL 7M5
+o&E)S}wP
Ht^MY
} W}B4^l
[{3WHS.
H -('!^
/* $s2Ty1
**SiteInfoBean.java etF?,^)h=g
*/ K@xp!
package NetFox; +kCVi
(2vR8
/_~b~3{u
public class SiteInfoBean { 6_/oVvd
!ZP1?l30
|u8hxa
private String sSiteURL; //Site's URL KLBV(`MS
private String sFilePath; //Saved File's Path -,jJ{Y~
private String sFileName; //Saved File's Name .XM3oIaW
private int nSplitter; //Count of Splited Downloading File rN#ydw:9
lh`inAt)"
A(AyLxB47*
public SiteInfoBean() <LM<,
{//nSplitter的缺省值为5 iqf+rBL
//default value of nSplitter is 5 $hB;r
this("","","",5); )f#@`lf[<
} Y{y #us1
^EU&6M2
=!NYvwg6;o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I%xrDiK97
{ }i_[wq{E&
sSiteURL= sURL; b7fP)nb695
sFilePath = sPath; u#=Yv|9
sFileName = sName; |E@Gsw
this.nSplitter = nSpiltter; S8j;oJ2d
uE:#m.Q
R=HN>(U
} S|T:rc(~
gUDd2T#
EVmQ"PKL'
public String getSSiteURL() e1{t qNJ
{ bj`cYL%
return sSiteURL; ]!H*oP8a*
} , 6\i
>VP\@xt(R[
#V-qS/ q"
public void setSSiteURL(String value) l ,)l"6OV
{ S4<@ji
sSiteURL = value; | (P%<
} P,AS`=z
Rf2/[
`h5HA-ud
public String getSFilePath() `g%]z@'+?
{ !$h%$se
return sFilePath; 18w[T=7)
} Zx25H"5j
Faa:h#
Q"8)'dL'
public void setSFilePath(String value) 7d/wT+f
{ n);2b\&
sFilePath = value; S|;a=K&hS
} _5M!ec
Ed#%F-1sX
EH3jzE3N
public String getSFileName() lsW.j#yE!
{ S$%/9^\jF
return sFileName; 6f6_ztTL
} aGp <%d
Hk2@X(
(o^V[zV
public void setSFileName(String value) 4M(w<f\5F
{ F~a5yW:R=)
sFileName = value; O|,+@qtH
} Fhn883
`(;d+fof
A4';((OXy
public int getNSplitter() V]H<:UE
{ 23+6u{
return nSplitter; mUr@w*kq|p
} I>/`W
3D\.Sj%
^'QcP5Fv
public void setNSplitter(int nCount) 9b]*R.x:$&
{ ~QBf78@Gf
nSplitter = nCount; $';'MoS
} S,AZrgh,"X
} $$ _uQf
hl}#bZ8]
KtEMH
/* /G[y 24 Q
**Utility.java pRc(>P3;
*/ WbH/K]/1)h
package NetFox; !nVX .m9
IvIBf2D;Q
NL&g/4A[a
public class Utility { l[G,sq"
3}g?d/^E3
(]1le|+
public Utility() M#S8x@U
{ ZM;EjS1
[$[t.m
ieBW 0eMi
} >;xEzc!W3*
rF~q"9
//线程睡眠 +*0THol-
public static void sleep(int nSecond) Zz?+,-$_*&
{ }WI24|`zM
try{ 86%weU/*
Thread.sleep(nSecond); n^&QOII@>
} R~RY:[5?w
catch(Exception e) *kyy''r
{ 8"8{Nf-"
e.printStackTrace (); xDADJ>u2K
} mSQ!<1PM
} yvDzxu
4vqu(w8 L
//日志 T>f-b3dk
public static void log(String sMsg) )STt3.
{ _%zU^aE
System.err.println(sMsg); W]Ph:O^5c
} PYz| d
$Uewv +
HwST^\Ao
public static void log(int sMsg) pNiqb+^nz
{ n+uq|sYVa
System.err.println(sMsg); )1x333.[c
} 0l 3RwWj
} 4QIvxH
3&' STPpW
`SW`d<+L
/* eHnC^W}|s
**TestMethod.java 82/iVm1
*/ K=(&iq!VO
package NetFox; }|SVt`n
STOE=TC>
Q^39Wk@
public class TestMethod { _l8oB)
H~V=TEj
!Aw.f!
public TestMethod() cuKgO{.GH
{ ///xx/weblogic60b2_win.exe $^ >n@Q@&L
try{ V;:A&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b/5~VY*T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tQl=
SiteFileFetch fileFetch = new SiteFileFetch(bean); q0c)pxD%`
fileFetch.start(); i;dr(c/ft
} in+`zfUJ9
catch(Exception e){e.printStackTrace ();} {?L}qV
JK_$A;Q
(U.&[B
} O0$ijJa|
wy-!1wd
El+]}D"
public static void main(String[] args) 54^hBejQ
{ ,~4(td+R7
new TestMethod(); dO8Z {wfs
} 6w]]KA
} 15s?QSKj
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