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)); a nIdCOh
} |@d7o]eM|
for(int i=0;i<nEndPos.length-1;i++) L#NPt4Sz+
{ YpNTq_S1,
nEndPos = nStartPos[i+1]; IClnh1=
} 8c~b7F \
nEndPos[nEndPos.length-1] = nFileLength; ~G"6^C:x
} Kq.)5%~>
} RJd55+h
ZEApE+m
?[VS0IBS
//启动子线程 eb:uh!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u1>|2D
for(int i=0;i<nStartPos.length;i++) N$_Rzh"9rr
{ @-u/('vpB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jh }3AoD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nwV\[E
nStartPos,nEndPos,i); %X#Wc:b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [>6:xGSe9X
fileSplitterFetch.start(); 'z+8;g.ekO
} >i`'e~%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }0f[x ?V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DmD*,[rD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =_v_#;h&
nEndPos = " + nFileLength); T.&^1qWWA
// fileSplitterFetch[nPos.length-1].start(); \9D '7/$I,
O{%y `|m
#M8"b]oh6
//等待子线程结束 eR5swy&
//int count = 0; 2;6p2GNSh
//是否结束while循环 WU}JArX9
boolean breakWhile = false; Zx`hutCv
5$zC,g*#
t|%iW%m4
while(!bStop) lfWxdi
{ *[_?4*F
write_nPos(); i<&2Ffvq
Utility.sleep(500); c: #1Aym
breakWhile = true; 9~u1fk{
!@bN
yQCfn1a)
for(int i=0;i<nStartPos.length;i++) @^%zh
{ [n66ZY#U]
if(!fileSplitterFetch.bDownOver) +KD~/}C%-
{ 4d6F4G4U
breakWhile = false; vp-)$f&
break; Pk*EnA)
} sFB; /*C
} zf2]|]*xz
if(breakWhile) \.Q"fd?a_D
break; f3*u_LO
*S{%+1F
i}M&1E
//count++; [Ma&=2h
//if(count>4) i' N
// siteStop(); z!t&zkAK
} ##yi^;3Y
#nn2odR
|4wVWJ7
System.err.println("文件下载结束！"); e9N 1xB
} | F:?
catch(Exception e){e.printStackTrace ();} ]36R_Dp
} TQbhK^]
_RjM .
'<8ewU
//获得文件长度 9I9J}&4
public long getFileSize() 3LX<&."z
{ 2<Ub[R
int nFileLength = -1; :^?ZVi59j
try{ ,R*ru*
URL url = new URL(siteInfoBean.getSSiteURL()); f*kT7PJG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xOD;pRZQ
httpConnection.setRequestProperty("User-Agent","NetFox"); m"@M~~bh
/[_>U{~P#
,?i#NN5p
int responseCode=httpConnection.getResponseCode(); `EV[uj&1S
if(responseCode>=400) k(hes3JV
{ ae#7*B
processErrorCode(responseCode); {f)",#
return -2; //-2 represent access is error q6/ o.j
} }^P(p?~
?u 9) GJO[
t</Kel|D
String sHeader; /koNcpJ
'du:Bxl`d4
(q3(bH~T)
for(int i=1;;i++) I)DLnnQQ
{ j3z&0sc2(0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z\O ,9
//Utility.log(in.readLine()); &|Z:8]'P
sHeader=httpConnection.getHeaderFieldKey(i); T4qbyui{
if(sHeader!=null) _0^<)OSY
{ 6}{2W<
if(sHeader.equals("Content-Length")) Jp_{PR:&
{ F]SexP4:A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); --.:eFE/
break; MT;<\T
} <@5#
} r~TiJ?8I
else hGD7/qTN
break; > NK?!!A_
} g"xLS}Al
} 4d9iAN
catch(IOException e){e.printStackTrace ();} -\AB!#fh
catch(Exception e){e.printStackTrace ();} S1%{/w
0qZ{:}`3
t'0r4&\
Utility.log(nFileLength); U}7$:hO"dX
z`5+BL,|ND
I+8m1*
return nFileLength; QTK\"
} F!j@b!J8
r'pFHX
_W tSZmW?
//保存下载信息（文件指针位置） NfS0yQPx
private void write_nPos() b 3D:w{l
{ ]#))#-&1
try{ $U"/.Mh\
output = new DataOutputStream(new FileOutputStream(tmpFile)); b"x;i\Z0%
output.writeInt(nStartPos.length); E{Y0TZ+
for(int i=0;i<nStartPos.length;i++) KdYT5VUM/
{ u.8vXc
// output.writeLong(nPos); NzNAhlXj3
output.writeLong(fileSplitterFetch.nStartPos); qV8;;&8r
output.writeLong(fileSplitterFetch.nEndPos); M)Tv(7
} a5z.c_7r
output.close(); Mz+|~'R
} rm(<?w%'?
catch(IOException e){e.printStackTrace ();} E^#|1Kpq
catch(Exception e){e.printStackTrace ();} U:gE:tf
} hG&RGN_<6+
7Cp>iWV
3 +BPqhzf
//读取保存的下载信息（文件指针位置） {Am\%v\
private void read_nPos() 6i%LM`8GEk
{ a%Cq?HZ7
try{ / D#vs9S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )Qb1$%r.
int nCount = input.readInt(); @l>\vs<
nStartPos = new long[nCount]; DTn=WGm)
nEndPos = new long[nCount]; %!p14c*J H
for(int i=0;i<nStartPos.length;i++) vy@;zrs
{ RAXqRP,iw
nStartPos = input.readLong(); 6bo,x
nEndPos = input.readLong(); : gv[X
} c{rX7+bN
input.close(); zO9|s}J8q
} H,KU!1p
catch(IOException e){e.printStackTrace ();} 9"_qa q
catch(Exception e){e.printStackTrace ();} OQW#BBet@
} tG{e(
6<sB
dq"b_pr;
private void processErrorCode(int nErrorCode) 1}KNzMHk9
{ (3c,;koRR
System.err.println("Error Code : " + nErrorCode); 52wq<[#tK
} dSk\J[D
^?&Jq_oU
:]=Y1*L\)
//停止文件下载 -md2Z0^ Kc
public void siteStop() Wq F(
{ g4RkkoZ>)
bStop = true; zu^?9k
for(int i=0;i<nStartPos.length;i++) ?ti7iBz?
fileSplitterFetch.splitterStop(); 8y~ Jn~t
\QHe0?6
E'JVf%)
} 0f;L!.eP
} @*%Q,$
//负责部分文件的抓取 jr"yIC_
**FileSplitterFetch.java g%1!YvS3v
*/ 91mXvQ:u
package NetFox; #x)G2T'?
(RWZ[-;)
V*U"OJ%
import java.io.*; DtXXfp@;
import java.net.*; Rj+}L ~"
G*\wu&7!
~;wSe[
public class FileSplitterFetch extends Thread { 1K09iB
8T$:^HW
gC<\1AIu
String sURL; //File URL OtY.s\m y
long nStartPos; //File Snippet Start Position }1z= C<
long nEndPos; //File Snippet End Position <)?H98S
int nThreadID; //Thread's ID 7{8!IcR #
boolean bDownOver = false; //Downing is over Xb#x^?|
boolean bStop = false; //Stop identical :}UWy?F
FileAccessI fileAccessI = null; //File Access interface }@!d(U*
mZ ONxR6q$
3(E"$Se,f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;9=9D{-4+
{ )&se/x+
this.sURL = sURL; c^A3|tCi
this.nStartPos = nStart; iWGgt]RJ
this.nEndPos = nEnd; 4kxy7]W
nThreadID = id; :NA cad
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o=q N+-N
} {~b]6}O
%q2dpzNW
_Dwn@{[(8
public void run() scJ`oc:<J
{ )amdRc
while(nStartPos < nEndPos && !bStop) = fuF]yL%
{ 7s<v06Wo
ehOF@IA_
D3;^!ln]D
try{ _o' jy^
URL url = new URL(sURL); Y]&HU) u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0*B_$E06
httpConnection.setRequestProperty("User-Agent","NetFox"); (.<Gde#
String sProperty = "bytes="+nStartPos+"-"; e>uV8!u
httpConnection.setRequestProperty("RANGE",sProperty); W_O,Kao
Utility.log(sProperty); .fUqsq
W-7yi`5
x%vt$dy*8
InputStream input = httpConnection.getInputStream(); b0m1O.&I_
//logResponseHead(httpConnection); YAC=V?U-#
xO"5bj
VqVP5nT'=
byte[] b = new byte[1024]; h9>~?1$lz
int nRead; HEht^/pJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fm*n>^P@Y
{ 0O!%NL[,
nStartPos += fileAccessI.write(b,0,nRead); W{=>c/
//if(nThreadID == 1) Gv?3}8Wp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); frc>0\
} E88_15'3D
1a/@eqF''
|~8iNcIS
Utility.log("Thread " + nThreadID + " is over!"); ~Jp\'P7*
bDownOver = true; rQj.W6w=
//nPos = fileAccessI.write (b,0,nRead); lv&<kYWY
} m#grtmyMrI
catch(Exception e){e.printStackTrace ();} bveNd0hN
} i\},
} H.O7Y
7 82NiVed
#u|;YC
//打印回应的头信息 Z;7f D
public void logResponseHead(HttpURLConnection con) W*`2lf
{ P[#V{%f*5
for(int i=1;;i++) SZ1+h TY7d
{ :g+R}TR[i
String header=con.getHeaderFieldKey(i); p,]Hs{R
if(header!=null) YUM%3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2ai \("?
Utility.log(header+" : "+con.getHeaderField(header)); )-2OraUm<
else xI}]q%V
break; n&FN?"I/]
} &P[eA u
} 3AX/A+2
9oc.`-e\?
4q~+K'Z
public void splitterStop() Ct$e`H!;
{ PO<4rT+B
bStop = true; DH)@8)C
} niqiDT/
QmT]~4PqS
5<,}^4wWZ
} %$!}MxUM
?G0=\U< o,
N}>`Xm5'
/* /G G QO$'
**FileAccess.java fo4j^,`
*//文件访问(定位，写) VAsaJ`vcb
package NetFox; > 9i@W@M
import java.io.*; m)= -sD
BU<A+Pe>
.QRQvtd.
public class FileAccessI implements Serializable{ ran Q_\
(!W:-|[K\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $MB56]W8
RandomAccessFile oSavedFile; t9Pu:B6
long nPos; ?J%$;"q
}yx'U 3
0K@s_C=n#
public FileAccessI() throws IOException TP'EdzAT
{ cDm_QYQ
this("",0); hgfCM
} 3xp%o5K
1ncY"S/VO
%]r@vjeyd
public FileAccessI(String sName,long nPos) throws IOException xo7H^!_
{ oizD:|
oSavedFile = new RandomAccessFile(sName,"rw"); )/Ee#)z*
this.nPos = nPos; iW.8+?Xq&
oSavedFile.seek(nPos); e@NS=U` <
} 6b6}HO
;W'y^jp]"
B~jl1g|
public synchronized int write(byte[] b,int nStart,int nLen) l?pZdAE
{ ,DXNq`24
int n = -1; cqRIi~`
try{ &N[~+"
oSavedFile.write(b,nStart,nLen); 2}b1PMpZG
n = nLen; >m44U 9
} ;]KGRT
catch(IOException e) O}Fp\"
{ 1EyM,$On
e.printStackTrace (); $X9-0-
} 4g$mz:vo
=HQH;c"
aqoT
return n; `5=0f}E
} e~i ?E
g5; W6QX
Ex&f}/F
} %kKe"$)0
&owBmpz
_udH(NC
/* !3kyPoq+
**SiteInfoBean.java fS w00F{T
*/ ?h<I:[oZ
package NetFox; VkRvmKYl
x6.an_W6
s'tmak-}|
public class SiteInfoBean { vz#rbBY*;
)?K3nr
df&d+jY
private String sSiteURL; //Site's URL :G9.}VrU
private String sFilePath; //Saved File's Path T&tCXi
private String sFileName; //Saved File's Name Tm.(gK
private int nSplitter; //Count of Splited Downloading File .B6$U>>NS^
4%KNHeaN
k$i76r
public SiteInfoBean() |9?67-
{//nSplitter的缺省值为5 ,CA,7Mu:
//default value of nSplitter is 5 5A>W;Q\4
this("","","",5); "m3u}!`3
} Y"K7$+5#\
X%h1r`h&
[6FCbzS_W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u;F++$=
{ &g\D-At
sSiteURL= sURL; =L#tSa=M"
sFilePath = sPath; <DvpqlT
sFileName = sName; s~Ni\SF
this.nSplitter = nSpiltter; f)({;,q
uV#/Lgw{M
8]YFlW9
} 7M<7^)9
di "rvw;R
: N>5{
public String getSSiteURL() V+nqQ~pJ&
{ dScit!T"
return sSiteURL; Io|NL6[
} B=(m;A#G
lw\OsB$
;E,%\<
public void setSSiteURL(String value) H/|Mq#K
{ "e&S*8QhM
sSiteURL = value; k =ru) _$2
} z%}^9
(fUXJ$
cZe,l1$
public String getSFilePath() :y"Zc1_E
{ j\P47q'v#
return sFilePath; w3:Y]F.ot
} _WVeb}
#c5G"^)z
NFDi2L>Ba
public void setSFilePath(String value) Y`uL4)hR5
{ A%Pjg1(uX
sFilePath = value; &\F`M|c
} g|9'Lk
R.Ao%VT
8*V3g_z
public String getSFileName() Co4QWyt:
{ _ncqd,&z
return sFileName; '&I.w p`^
} t9Ht 54
|dsd5Vdr
d(jd{L4d
public void setSFileName(String value) w-Y-;*S
{ ZL:nohB
sFileName = value; +Tf,2?O
} :tu6'X\k
63#Sf$p{v
&y[Od{=
public int getNSplitter() j="{^b
{ 1[ ME/r
return nSplitter; z:ue]7(.
} HpiP"Sl
C:"Al-
y[UTuFv~Q
public void setNSplitter(int nCount) npkE[JE:
{ yEJ}!/
nSplitter = nCount; EEEYNu/4/
} <{Wsh#7}.
} \S{ise/U
9fp1*d
[[}KCND
/* QmvhmsDL
**Utility.java ArDkJ`DE
*/ vrXUS9i.
package NetFox; %G1kkcdH<
B<SuNbR
)[|`-M~u
public class Utility { Smzy EMT
g)u ~GA*=
iq)4/3"6
public Utility() y/Fv4<X
{ 6J9^:gXW~
f}PT3
ng(STvSh:
} (]n^_G#-$
8_US.52V
//线程睡眠 dE=4tqv-r
public static void sleep(int nSecond) ^31X-}tv
{ Q&}`( ]k
try{ -&I)3
Thread.sleep(nSecond); -/*-e /+b
} ]mYT!(}
catch(Exception e) v)mO"\
{ ZW{pO:-
e.printStackTrace (); ^a#Vp
} _5 Zhv-7
} p}$VBl$'
BUqe~E|I
//日志 ~mP#V
public static void log(String sMsg) W-ErzX
{ 5(R ./
System.err.println(sMsg); 1K.i>]}>
} Q%o:*(x[O
*~~ >?
PTfTT_t
public static void log(int sMsg) o(Yj[:+m
{ T$RVz
System.err.println(sMsg); -$WU-7`
} 59A@~;.F
} -\O%f)R
)F Q '^
B~K@o.%
/* 1|_jV7`Mz
**TestMethod.java jHBzZ!<
*/ xPoI+,
package NetFox; $Zf hQ5bat
:_E=&4&g
=:OS"qD3l
public class TestMethod { s4uZ;
V+j58Wuf
s{\USD6
public TestMethod() lArYlR}
{ ///xx/weblogic60b2_win.exe eT* )r~
try{ @}k5rcQ*/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =oz$uD}?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tfW*(oU
SiteFileFetch fileFetch = new SiteFileFetch(bean); $Tci_(V=F
fileFetch.start(); ?UCK
} T<1*R>el
catch(Exception e){e.printStackTrace ();} BM9J/24
y,e#e`
is@8x!c
} nA$zp
1;Bgtv$
w9h`8pt
public static void main(String[] args) L6S!?t.{Yv
{ vDl6TKXcu
new TestMethod(); `R]B<gp
} ,U':=8
} !lf'gW
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