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)); r7tN(2;5
} LEM{$Fxo&
for(int i=0;i<nEndPos.length-1;i++) lFWN[`H
{ 2#4_/5(j*
nEndPos = nStartPos[i+1]; ^}XKhn.S'
} O?uT'$GT
nEndPos[nEndPos.length-1] = nFileLength; K\ww,S
} ETP}mo
} ;!<WL@C~
)!1; =
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//启动子线程 0G/VbS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :uZfdu
for(int i=0;i<nStartPos.length;i++) nZ>bOP+,
{ \Nc/W!r*9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fP`g#t)4Tu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^'S0A=1
nStartPos,nEndPos,i); rs01@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9X8{"J
fileSplitterFetch.start(); /#Y)nyE
} QDlEby m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s)$N&0\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?3!"js B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7%Zl^c>q
nEndPos = " + nFileLength); JZp*"UzQr
// fileSplitterFetch[nPos.length-1].start(); F]~rA! g1
OL]^4m
= GirUW D
//等待子线程结束 r}OK3J
//int count = 0; .BGM1ph}~
//是否结束while循环 yp=Hxf
boolean breakWhile = false; %dTkw+J
YmM+x=G:
@Md%gEh;&
while(!bStop) ~\tI9L?|A
{ ^Yei9bXl
write_nPos(); <8MKjf
Utility.sleep(500); bkkhx,Oi[G
breakWhile = true; OKfJ
EWPP&(u3
<Vyv)#32o3
for(int i=0;i<nStartPos.length;i++) <}b`2/wP
{ <,d.`0:y
if(!fileSplitterFetch.bDownOver) _[-+%RP
{ 2wE?O^J
breakWhile = false; $:"r$7
break; W B)<B
} #%k!`?^fbK
} ~<Z;)e
if(breakWhile) @-bX[}.
break; 2g1[E_?
[-!
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//count++; cZKK\hf<
//if(count>4) ^"\ jIP
// siteStop(); `k65&]&d
} W HO;;j
T9]|*~ ,T
yfeX=h
System.err.println("文件下载结束！"); U'zW; Lt
} Z<ozANbk
catch(Exception e){e.printStackTrace ();} 78>)<$+d
} $5y%\A
U>6MT@\
$$~x: iN
//获得文件长度 :G9+-z{Y&
public long getFileSize() v!?bEM3D
{ T6JN@:8
int nFileLength = -1; A_1cM#4
try{ Ar4E $\W
URL url = new URL(siteInfoBean.getSSiteURL()); R%o:'-~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qEr2Y/:i"
httpConnection.setRequestProperty("User-Agent","NetFox"); }\}pSqW
[Hz_x(t26
:#58m0YLA:
int responseCode=httpConnection.getResponseCode(); fv_}7t7
if(responseCode>=400) F+Rtoq|
{ $u_0"sUV
processErrorCode(responseCode); 'Ca6cm3Tg
return -2; //-2 represent access is error L^} Z:I
} m8eyAvi6
$A"kHS7T
9{|JmgO!
String sHeader; BJ!b LQ
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:@)UI,
for(int i=1;;i++) k@U8K(:x
{ QU^*(HGip
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w~a^r]lPW
//Utility.log(in.readLine()); dt(~)*~R
sHeader=httpConnection.getHeaderFieldKey(i); 6s\niro2
if(sHeader!=null) 0xrr9X<
{ /^^t>L
if(sHeader.equals("Content-Length")) O,R5csMh
{ w naP?|/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '^ bB+
break; O6Bs!0,
} 6nh!g
} (n+2z"/
else GL$!JKWp
break; "V-k_d "
} 3~Od2nk(x
} E^w2IIw
catch(IOException e){e.printStackTrace ();} `s5<PCq
catch(Exception e){e.printStackTrace ();} H"czF
lxb+0fiN
Qd;P?W6
Utility.log(nFileLength); )9F-h8 &"
wBZ=IMDu\
LVKvPi
return nFileLength; *I6z;.#
} g^|}e?
}U3+xl6g
T<(1)N1H`
//保存下载信息（文件指针位置） ITJ{]7N
private void write_nPos() K ;\~otR^
{ `i5U&K. 7
try{ 4?Pdld
output = new DataOutputStream(new FileOutputStream(tmpFile)); eKjmU| H
output.writeInt(nStartPos.length); gY\X?
for(int i=0;i<nStartPos.length;i++) hhd%j6
{ $/;D8P5/&=
// output.writeLong(nPos); s}Phw2`1U
output.writeLong(fileSplitterFetch.nStartPos); ,Y *unk<S
output.writeLong(fileSplitterFetch.nEndPos); K~'!JP8@
} ~hK7(K
output.close(); `roos<F1D
} 8:=&=9%
catch(IOException e){e.printStackTrace ();} 3FRz&FS:j
catch(Exception e){e.printStackTrace ();} &*2\1;1tB
} '%Og9Bgd+
X`#,*HkK
D![42H+-Qd
//读取保存的下载信息（文件指针位置） nOq?Q
private void read_nPos() ql"&E{u?
{ tLCu7%P>
try{ ^b|Z<oF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &"HxAK)f
int nCount = input.readInt(); <Sds5 d
nStartPos = new long[nCount]; DV+M;rs
nEndPos = new long[nCount]; ;W%nBdE6|
for(int i=0;i<nStartPos.length;i++) %smQ`u|
{ F6>K FU8
nStartPos = input.readLong(); .OhpItn
nEndPos = input.readLong(); CTawXHM
} :QKxpHi
input.close(); :"m~tU3&
} e7e6b-"_2
catch(IOException e){e.printStackTrace ();} 337y,;
catch(Exception e){e.printStackTrace ();} YywiY).]@
} B ~u9"SR.
[/dGOl+
kk|7{83O
private void processErrorCode(int nErrorCode) (al.7VA;9
{ b#ga
System.err.println("Error Code : " + nErrorCode); ]vj.s/F~
} UN ;9h9
/V'^$enK!}
:`u?pc27Sm
//停止文件下载 /|7@rH([{
public void siteStop() [6 d~q]KH
{ }YV,uJH[
bStop = true; TUE*mDRmP
for(int i=0;i<nStartPos.length;i++) %v}SJEXFp
fileSplitterFetch.splitterStop(); gut[q
`Fn"%P!
:Y? L*
} &d,chb(
} 4%!#=JCl
//负责部分文件的抓取 &[u>^VO8
**FileSplitterFetch.java E}Ir<\
*/ 3=[#(p:
package NetFox; 99QMMup
N$'/J-^
yf|,/{S
import java.io.*; (CUrFZT$
import java.net.*; \.0cA4)[$
b5!\"v4c
0[A4k:
public class FileSplitterFetch extends Thread { 4Vv~
C%c}lv8;^
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String sURL; //File URL Z|78>0SAt
long nStartPos; //File Snippet Start Position 01N]|F:
long nEndPos; //File Snippet End Position cL+--$L
int nThreadID; //Thread's ID Iw07P2
boolean bDownOver = false; //Downing is over iJ8 5okv'
boolean bStop = false; //Stop identical @.rVg XE=!
FileAccessI fileAccessI = null; //File Access interface \o|5/N
s,5SWdb\v
yQP!Vt^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U,G!u=+
{ $x5,Oen
this.sURL = sURL; Z`_`^ \"
this.nStartPos = nStart; D\~s$.6B
this.nEndPos = nEnd; G,jv Mb`+
nThreadID = id; ?nVwT[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o0yyP,?yh
} @M]uUL-ze
O~p@87aq
B/:+(|
public void run() ,]:vk|a#;
{ 6}V)\"u&
while(nStartPos < nEndPos && !bStop) q5Bj0r[/o
{ Z`FEB0$
fPW|)e"
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try{ Mx-? &
URL url = new URL(sURL); =)h<" 2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "PFczoRZ
httpConnection.setRequestProperty("User-Agent","NetFox"); ;-aF\}D@n
String sProperty = "bytes="+nStartPos+"-"; &1=Je$,
httpConnection.setRequestProperty("RANGE",sProperty); -K"" 4SC2
Utility.log(sProperty); PIZnzZ@Z;
mYU7b8x_
MC 8t"SB
InputStream input = httpConnection.getInputStream(); 'zRi;:UHA
//logResponseHead(httpConnection); P^lzl:|
.J/x@
r>>4)<C7J
byte[] b = new byte[1024]; j{U#g8
int nRead; f*Xum[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sIM^e
{ z%4E~u10
nStartPos += fileAccessI.write(b,0,nRead); 4qd =]i
//if(nThreadID == 1) O^Y}fo'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AX`>y@I
} "mbjS(-eg
.C6wsmQ
!=)R+g6b
Utility.log("Thread " + nThreadID + " is over!"); b I%Sq+"}
bDownOver = true; (f-Mm0%[
//nPos = fileAccessI.write (b,0,nRead); +t9$*i9`L
} ^|b]E
catch(Exception e){e.printStackTrace ();} nnzfKn:J
} =XRTeIZ
} #hKaH -j
N7wKaezE
B4&K2;fg_
//打印回应的头信息 |9fvj6?Y
public void logResponseHead(HttpURLConnection con) 8C[W;&Y=
{ 6~oo.6bA
for(int i=1;;i++) mY)Y47iL
{ +i\ +bR
String header=con.getHeaderFieldKey(i); kVqRl%/3Tb
if(header!=null) >V01%fLd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !,SGKLs.m
Utility.log(header+" : "+con.getHeaderField(header)); *X_-8 ^~
else 71RG1,
break; C;m,{MD
} ytmFe!
} qe/|u3I<lF
KTmduf7DL
#"T< mM7
public void splitterStop() F2N)|C<
{ 1#Ls4+]5
bStop = true; 96VJE,^h
} 8E/wUN,Lxj
Vgj&hdbd
`U.VfQR:
} 51)Q&,Mo#
K3;lst>4
TJ5g?#Wul
/* G $F3dx.I
**FileAccess.java Uo~-^w}
*//文件访问(定位，写) ?*nFz0cs^
package NetFox; u2FD@Xq?
import java.io.*; &*e(
CyWMr/'
{hNvCk
public class FileAccessI implements Serializable{ `Z'h[-2`
d3IMQ_k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <mk'n6B
RandomAccessFile oSavedFile; yu~o9
long nPos; /uNgftj
$;V?xZm[
FG6bKvEQm^
public FileAccessI() throws IOException \y^Ho1Fj
{ y$Y*%D^w
this("",0); \-h%z%{R
} 'f "KV|
HtN!Hgpwg
d41DcgG'j(
public FileAccessI(String sName,long nPos) throws IOException HT% =o}y
{ :g+5cs
oSavedFile = new RandomAccessFile(sName,"rw"); GdlzpBl
this.nPos = nPos; 'LyEdlC]
oSavedFile.seek(nPos); ;Pd nE~
} 7C::%OF~7
5j{jbo=!
wJr5[p*M
public synchronized int write(byte[] b,int nStart,int nLen) ~Q3y3,x
{ RP9jZRDbZ
int n = -1; *?o`90HHP[
try{ "dItv#<:}
oSavedFile.write(b,nStart,nLen); K!cLEG!G
n = nLen; ;dR4a@
} Nj^:8]D)0
catch(IOException e) :p|wo"=@Ge
{ "B34+fOur
e.printStackTrace (); d8p<f+
} knS(\51A
n5G|OK0,
h't!1u
return n; s{:l yp
} qtI42u{
|3:e$
er44s^$
} {}A1[Y|
g)M"Cx.
U%?
/* 5Kw$QJ/
**SiteInfoBean.java >[A7oH
*/ %0MvCm
package NetFox; [WXa]d5Y
)%6h9xyXt
^fq^s T.$
public class SiteInfoBean { O`rKxP
= 9K5f#;e
!C3ozZ<
private String sSiteURL; //Site's URL *]#(?W.$w
private String sFilePath; //Saved File's Path +WTO_J7
private String sFileName; //Saved File's Name qPvWb1H:
private int nSplitter; //Count of Splited Downloading File # ^q87y
S!@h\3d8{
m~;}8ObQE
public SiteInfoBean() ">|G^@|:A
{//nSplitter的缺省值为5 O+w82!<:
//default value of nSplitter is 5 ^lP;JT?
this("","","",5); 5B)z}g^h
} }1}L&M@
w40 -K5wt>
cqSo%a2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5BAGIO<w
{ M8y:FDX
sSiteURL= sURL; vLT$oiN[c
sFilePath = sPath; Iss)7I
sFileName = sName; r Y#^C
this.nSplitter = nSpiltter; :oeDksld
- xE%`X
;%`oS.69
} ]Dd}^khv
CxbGL
1{Kv
public String getSSiteURL() BTAt9Z8qK
{ DV!10NqUr
return sSiteURL; /73ANQ"
} jV 982Y
'Z}3XVZEN
3[r9v!l
public void setSSiteURL(String value) ZFFKv
{ jM5w<T-2/
sSiteURL = value; GC3WB4iY@U
} AA &>6JB{
<_>xkQbn2
L}Rsg'U
public String getSFilePath() I ]HP
{ 8:gUo8
return sFilePath; 4Je[!X@C
} Y2d(HD@
LM2S%._cj;
z~($ "
public void setSFilePath(String value) X6-;vnlKN
{ EC`=nGF
sFilePath = value; TJ_pMU
} iY;>LJmp
>`=9So_J
S3N+9*iK
public String getSFileName() (8td0zq
{ r~YxtBZH+
return sFileName; BIY"{"hJ
} 3k# h!Z
PR3&LI;B*
]S+KH \2
public void setSFileName(String value) QruclNW{Bv
{ h1Nd1h@-
sFileName = value; ;)23@6{R%
} M97MIku~9
wBI>H 7A
MRN=-|fV^
public int getNSplitter() | {Tq/
{ &j?+%Y1n@
return nSplitter; FjV)QP H
} MG:eI?G/'
[9d4 0>e
7-VP)|L#G
public void setNSplitter(int nCount) $!7$0WbC
{ k*K.ZS688
nSplitter = nCount; a\B'Qe+
} UW'@3#<?
} trz&]v=:
o@[oI\Vr!
iI Dun Ih
/* L>&9+<-B
**Utility.java xQDWnpFc
*/ {F ',e~}s
package NetFox; ^4Tf6Fw#
_)ZxD--Qg
|+Cd2[hN
public class Utility { +?v2MsF']
bKt4
qFXx/FZ
public Utility() W!V-m
{ w>wzV=R
j:7AVnt
q0{_w
} ]cM,m2^2
(W |;gQ
//线程睡眠 a= (vS
public static void sleep(int nSecond) e.WKf,e"X
{ &3 *#h
try{ {gb` %J
Thread.sleep(nSecond); 6 IRa$h>H
} TTGWOC
catch(Exception e) zy`T! $
{ H'}6Mw%ra
e.printStackTrace (); 0i(c XB
} '7 t:.88
} 5c$\DZ(
nh+Hwj#(x
//日志 v8K`cijSS
public static void log(String sMsg) o(yyj'=(
{ QzxEkTc;
System.err.println(sMsg); @H$Sv
} bnZ H
kS4YxtvB
BS3{TGn
public static void log(int sMsg) W'6sY@0m
{ 3)y=}jw
System.err.println(sMsg); }/QtIY#I
} 4UHviuOo8
} xdh%mG:?
<R?S
NAOCQDk{
/* pKU(4&BxX
**TestMethod.java CA5T3J@vAQ
*/ _'l"Dk
package NetFox; }Fsr"RER@{
n`V?n
[I}z\3Z %
public class TestMethod { =#vJqA
-us:!p1T
V''fmWo7
public TestMethod() k*D8IB
{ ///xx/weblogic60b2_win.exe ,(&Fb~r]
try{ Zv(6VVj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dus!Ki~8(t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w c
SiteFileFetch fileFetch = new SiteFileFetch(bean); m\70&%v
fileFetch.start(); 2#ZqGf.'v
} X#HH7V>
catch(Exception e){e.printStackTrace ();} 2@IL n+#
Tv6y+l
_-rC]iQJ55
} *Q#oV}D_
w[$oH^7
4o"?QV:
public static void main(String[] args) t+K1ArQc
{ u%lUi2P2E
new TestMethod(); Kv)}
} ":q+"*fy
} {rK]Q! yj
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