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)); EZQ+HECpK
} e.|RC
for(int i=0;i<nEndPos.length-1;i++) hRIS[#z;U
{ vx}Z
nEndPos = nStartPos[i+1]; Ej09RO"pB
} 5|G3t`$pa
nEndPos[nEndPos.length-1] = nFileLength; sJK:xk.6!
} (Zg'pSs)
} :*:fun
&d3'{~:
I@Z*Nu1L
//启动子线程 np\2sa`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *M<BPxh0w]
for(int i=0;i<nStartPos.length;i++) Dh(T)yc
{ !riMIl1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f\_!N "HW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [j]J_S9jJ
nStartPos,nEndPos,i); ec4%Wk2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]!G>8Rc
fileSplitterFetch.start(); <`j[;>O
} 2vdQ&H4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *a,.E6C*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |4> r"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =#2qX>?
nEndPos = " + nFileLength); ^}/ E~Sg7\
// fileSplitterFetch[nPos.length-1].start(); W$Q)aA7
,9tbu!Pvq
%_R|@cyD
//等待子线程结束 ^Xy$is3
//int count = 0; ,x"yZ
//是否结束while循环 dwbY"t[9
boolean breakWhile = false; #C;zS9(]B
P,;b'-5C
pebx#}]p-
while(!bStop) -C-OG}XjI
{ 9#T%bB"J
write_nPos(); ddq 1NW
Utility.sleep(500); 1;:t~Y
breakWhile = true; @23RjoK
P[I*%
d?&!y]RS#
for(int i=0;i<nStartPos.length;i++) "K+N f
{ vgA!?P3
if(!fileSplitterFetch.bDownOver) fZV8o$V
{ +V);'"L
breakWhile = false; U]!.~ji3
break; RJ}yf|d-C
} fJ&<iD)6
} [zTYiNa
if(breakWhile) RTgA[O4J
break; Ns|V7|n]
u->@|tEq
OT}Yr9h4
//count++; O`[iz/7m
//if(count>4) yEpN,A
// siteStop(); $mI:Im`s
} 5}MlZp
ELrZ8&5G
"gbnLKs
System.err.println("文件下载结束！"); q?Ku}eID3
} UC+7-y,
catch(Exception e){e.printStackTrace ();} le^_6|ek
} > 0Twr
BsK|:MM]
aFr!PQp4{
//获得文件长度 k99gjL`
public long getFileSize() 6a%:zgkOpu
{ -_EY$?4
int nFileLength = -1; )`s;~_ZZ
try{ >^H'ZYzw
URL url = new URL(siteInfoBean.getSSiteURL()); Cwsoz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ck3QrfM
httpConnection.setRequestProperty("User-Agent","NetFox"); =|gJb|?w
3Zaq#uA
])QO%
int responseCode=httpConnection.getResponseCode(); jV4hxuc$
if(responseCode>=400) ~X~xE]1o|U
{ l~fh_IV1
processErrorCode(responseCode); xgtJl}L
return -2; //-2 represent access is error B%eDBu ")
} ^Cc8F3os=
YHO;IQ5
M$&WM{Pr^
String sHeader; Q3BLL`W~
zM_DE
x5fgF;
for(int i=1;;i++) rb *C-NutE
{ J})$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wuIsO;}/9
//Utility.log(in.readLine()); c_qcb7<~.
sHeader=httpConnection.getHeaderFieldKey(i); -- i&"
if(sHeader!=null) \'; t*
{ ;# R3k
if(sHeader.equals("Content-Length")) nIV.9#~&
{ ;w+:8<mM}a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5Cc6, ]
break; Dm|gSv8d,
} g{A3W) [ b
} <ELziE~>V
else BcZEa^^~os
break; %z-dM` i
} f[JI/H>
} d s|8lz,
catch(IOException e){e.printStackTrace ();} ?jNF6z*M6
catch(Exception e){e.printStackTrace ();} qeQC&U y;
Kf05<J!
&*(n<5wt
Utility.log(nFileLength); 2I]]WBW#:
rV8(ia
#$rf-E5g-K
return nFileLength; 00`bL
} gro7*<
ilDJwZg#
:SQDqG
//保存下载信息（文件指针位置） < 72s7*Rv
private void write_nPos() Yl)eh(\&J
{ |u^)RB
try{ 0(Y%,q
output = new DataOutputStream(new FileOutputStream(tmpFile)); wUru1_zjO
output.writeInt(nStartPos.length); Ud>`@2
for(int i=0;i<nStartPos.length;i++) !sg%6H?}
{ $xRo<,OV+
// output.writeLong(nPos); zQL!(2
output.writeLong(fileSplitterFetch.nStartPos); UfK4eZx*`
output.writeLong(fileSplitterFetch.nEndPos); &Q'\WA'
} lQh E]m>+
output.close(); CDQJ bvx
} I;Al?&uw
catch(IOException e){e.printStackTrace ();} \yih 1Om>~
catch(Exception e){e.printStackTrace ();} U9<_6Bsd
} _-@ZOhw&
*C4~}4WT\
%'{V%IXQ
//读取保存的下载信息（文件指针位置） -!XrwQyk
private void read_nPos() "2ZIoa!^
{ 5*JV )[
try{ {[Uti^)m%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %:" RzHN
int nCount = input.readInt(); Jq#[uX
nStartPos = new long[nCount]; hf_R\C(c
nEndPos = new long[nCount]; |f"-|6
for(int i=0;i<nStartPos.length;i++) q$MHCq;
{ |9+bSH9
nStartPos = input.readLong(); _n< LVdE
nEndPos = input.readLong(); >lA7*nn
} -`-ACWeNV
input.close(); jv*Dg (
} pZu?V"R
catch(IOException e){e.printStackTrace ();} =RQ )$ %
catch(Exception e){e.printStackTrace ();} IM[54_I
} AU0$A403
Q8 -3RgAw
ZvUp#8x(3
private void processErrorCode(int nErrorCode) 2#'rk'X,K
{ |d~B]65t
System.err.println("Error Code : " + nErrorCode); V)2"l"Kt
} +7Sf8tg\
&\&'L|0F
3sS=?q
//停止文件下载 NV&;e[z
public void siteStop() 0FG5_t"",\
{ hbVE; 9
bStop = true; |)^clkuGX
for(int i=0;i<nStartPos.length;i++) !$D&6M|C8l
fileSplitterFetch.splitterStop(); w|&,I4["
:0B |<~lX
40 A&#u9o
} UE"7
} HvAE,0N
//负责部分文件的抓取 j?=VtVP
**FileSplitterFetch.java H9sZR>(^
*/ $b4*/vMr
package NetFox; d?JAUbqy
+VwV5iy[`
l<$rqz3D
import java.io.*; D`V6&_.p
import java.net.*; +z+F-
et@">D%;]
'^hsH1
public class FileSplitterFetch extends Thread { :]EP@.(
=\M)6"}y}
E yd$fcRK
String sURL; //File URL @o`sf-8x
long nStartPos; //File Snippet Start Position +IvNyj|
long nEndPos; //File Snippet End Position &xgZFSq
int nThreadID; //Thread's ID 5xhM0(
boolean bDownOver = false; //Downing is over [C~fBf5
boolean bStop = false; //Stop identical FU[*8^Z
FileAccessI fileAccessI = null; //File Access interface a-fv[oB
Og+)J9#
>Q&CgGpW$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E\ tL
{ [9LxhPi
this.sURL = sURL; 8IeI0f"l)
this.nStartPos = nStart; '[%jjUU
this.nEndPos = nEnd; ?qy*s3j'M
nThreadID = id; Jl\'V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3]N q@t
} N5yJ'i~,M
>A<Df
=`JW1dM
public void run() cbfDB^_
{ z23#G>I&
while(nStartPos < nEndPos && !bStop) 46ILs1T6
{ l/[pEUYU
V5~fMsse
)u<eO FI+
try{ su}&".e^
URL url = new URL(sURL); Z A[)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 00"CC
httpConnection.setRequestProperty("User-Agent","NetFox"); /\d(c/,4
String sProperty = "bytes="+nStartPos+"-"; rjXnDh]MC
httpConnection.setRequestProperty("RANGE",sProperty); *u}'}jC1X
Utility.log(sProperty); 3\1#eK'TK.
fSbS(a
'(tj[&aL
InputStream input = httpConnection.getInputStream(); @`6}`k
//logResponseHead(httpConnection); X6'H`E[
jKS!'?
QPX`l0V
byte[] b = new byte[1024]; 3EI]bmi~
int nRead; S.1(3j*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7H4L-J3
{ P:qz2Hw
nStartPos += fileAccessI.write(b,0,nRead); nX)f'[ 7
//if(nThreadID == 1) g@Ld"5$^2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &Bm&i.r
} 02(h={
7 I@";d8~
qIz}$%!A
Utility.log("Thread " + nThreadID + " is over!"); mf$Sa58
bDownOver = true; g &*mozs
//nPos = fileAccessI.write (b,0,nRead); f\ 'T_
} i@XB&;*c\
catch(Exception e){e.printStackTrace ();} &~'S)Nun
} i*'Z3Z)
} ;?zF6zvQ
\X5 3|Y;=
VtWT{y5Ec
//打印回应的头信息 _W}(!TKO
public void logResponseHead(HttpURLConnection con) TU%bOAKF\
{ "T7>)fbu
for(int i=1;;i++) zSKKr?{
{ GB=bG%Tb
String header=con.getHeaderFieldKey(i); bJwc1AJgH
if(header!=null) [ZD[a6(94
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hXc}r6<B
Utility.log(header+" : "+con.getHeaderField(header)); AX;c}0g
else '$?du~L-
break; 'AWp6L@
} F5U|9<
} sBU_Ft
Wxn#Rk#>
JCD?qeTg
public void splitterStop() or!!s 5[d
{ e}e6r3faz
bStop = true; p31oL{D
} WFem#hq
7E\g &R.
8ljuc5,J
} uFo/s&6K
kM;o0wi
l sr?b
/* +(&|uq^
**FileAccess.java XhN{S]Wn
*//文件访问(定位，写) </=3g>9Z
package NetFox; 5{X*a
import java.io.*; `7\H41%\pp
A?r^V2+j
eF5;[v
public class FileAccessI implements Serializable{ ^BiPLQ
n]iyFZ`9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %J!NL0x_
RandomAccessFile oSavedFile; +{e`]t>_
long nPos; G\ex^&M
,56;4)cv
c0ZaFJ
public FileAccessI() throws IOException N&m_e)E5c
{ 5gshKmt_
this("",0); V&iS~V0.
} wDKELQ(yH
{OP~8e"
'yr{^Pek
public FileAccessI(String sName,long nPos) throws IOException ~b6GrY"vB
{ ? |VysJ
oSavedFile = new RandomAccessFile(sName,"rw"); TF2KZL#A|
this.nPos = nPos; pV=@sz,G
oSavedFile.seek(nPos); 0>FE%
} Y{+3}drJE
*)D1!R<\,R
:j,}{)5=
public synchronized int write(byte[] b,int nStart,int nLen) $DE&J4K
{ CmHyAw(
int n = -1; `{o$F ::(
try{ RG}}Oh="v
oSavedFile.write(b,nStart,nLen); ,H{={aln
n = nLen; 4.w"(v9V
} MUwxgAG`G
catch(IOException e) J|5Ay1eF-
{ dB7ZT0L\
e.printStackTrace (); F 7LiG9H6`
} t^U^Tr
SiTeB)/
M1{(OY(G
return n; s[X B#)H4
} $>r5>6
oY.\)eJ~>
iRt*A6`m+
} vaB!R 0
iRve)
taDQ65
/* " "%#cDR
**SiteInfoBean.java LGVlc@0'
*/ |,sMST%
package NetFox; $^h?:L:1n
B}\BeFt'
t9` Ed>a
public class SiteInfoBean { Ct!S Tk[2
>lLo4M 3
A ~&+F>Z
private String sSiteURL; //Site's URL X"<|Z]w
private String sFilePath; //Saved File's Path @GeHWv
private String sFileName; //Saved File's Name Ep ">v>"
private int nSplitter; //Count of Splited Downloading File bV6V02RF
2Y+:,ud\
ri=+(NKo-
public SiteInfoBean() doLNz4W
{//nSplitter的缺省值为5 wW5Yw i
//default value of nSplitter is 5 i/$SN-5}1
this("","","",5); ,YB1 y)x
} |^Kjz{
5[R?iSGL1
l$M +.GB<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gtYRV*^q
{ "8/dD]=f^a
sSiteURL= sURL; m~>@BCn;
sFilePath = sPath; [W;[v<E;
sFileName = sName; ^yVl"/
this.nSplitter = nSpiltter; 1;&T^Gdj
nk/vGa4
D=&K&6rr
} ?,XC=}
9@y3IiZ"}
2w4MJ,Uw
public String getSSiteURL() ri+U0[e3
{ vr4S9`,
return sSiteURL; Ue7 6py9
} [:B*6FXMN~
<|H?gfM
m UgRm]
public void setSSiteURL(String value) XTo8,'UaP
{ E{>`MNj
sSiteURL = value; jBRPR R0
} 1X&B:_
vGN3 YcH
;J=:IEk
public String getSFilePath() aR)?a;}H
{ 7>,rvW:]
return sFilePath; XeU<^ [
} fA^SD"xf
)`Ed_F}k
p+<}YDMb
public void setSFilePath(String value) K\^&+7&zVg
{ t.U{Bu P
sFilePath = value; Pz`hX$
} \]8i}E1
/^4"Qv\@/
VQ<5%+
public String getSFileName() ?D=8{!R3
{ gp/YjUH7k8
return sFileName; n(R_#,Hs
} sFElD ]|
m&Sp1=*Ejy
@q)E=G1<o0
public void setSFileName(String value) JIV8q HC
{ XKSX#cia
sFileName = value; q%S8\bt
} !<r8~A3!(
eP= j.$
tcOnM w
public int getNSplitter() v}P!HczmMP
{ &t6Tcy
return nSplitter; N-QCfDao
} `~nCbUUee
=]b9X7}
gZ`DT
public void setNSplitter(int nCount) `bqzg
{ 7$_ :sJ
nSplitter = nCount; 7I3:u+
} Jck"Ks
} kl<g;3
) ,Npv3(
?Aw3lH#:
/* Qlh?iA
**Utility.java $G3@< BIN
*/ ^PQM;"
package NetFox; os**hFPk;1
O`(U/?
o#}mkE87
public class Utility { \ V?I+Gc
}Vl^EAR
V6*?$o
public Utility() 1b[NgOXY=
{ c F=P!2@
SQ<f
KN, 4@4
} jY+Do:#/wO
4J8Dh;a`
//线程睡眠 5/(sjMB
public static void sleep(int nSecond) a_%>CD${t
{ Q>%E`h
try{ o9+Q{|r
Thread.sleep(nSecond); WZK :.y
} }`]]b+_b>@
catch(Exception e) #Fzb8Yo
{ (9'be\
e.printStackTrace (); QgZJ`G--
} vJThU$s-
} vZk9gGjk
`^e*T'UPl
//日志 C P&o%Uc*
public static void log(String sMsg) )_Iz>)
{ {aIZFe}B
System.err.println(sMsg); 3'^S3W%
} ?i%nMlcc
b9#m m
JV%nH!Fs
public static void log(int sMsg) }.t^D|
{ ^O \q3HA_4
System.err.println(sMsg); :D4];d>1
} 8]]@S"ZM,\
} 5Pqt_ZWy
' &N20w
cNeiD@t3V&
/* KBj@V6Q
**TestMethod.java y#e ?iE@
*/ !ew6 n I
package NetFox; 2Pz5f
D6:DrA:
kQ[Jo%YT?E
public class TestMethod { 2-7Z(7G{ F
&Ea"hd
WL/5 oj
public TestMethod() R#LGFXUj
{ ///xx/weblogic60b2_win.exe g-|Kyhr?=
try{ 4+I 3+a"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =h7[E./U1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |?yE^$a
SiteFileFetch fileFetch = new SiteFileFetch(bean); oN ;-M-(
fileFetch.start(); pU@YiwP"]x
} L6xB`E9
catch(Exception e){e.printStackTrace ();} AoU_;B\b%
q#m!/wod
:mn(0 R~
} pJocI_v9
->3uOF!q
RUqO!s~#rY
public static void main(String[] args) KG-y)qXu
{ ph+M3q(z
new TestMethod(); h,~tXj
} $$\V2%v
} ;Rs.rl>;t/
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