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)); NAJ '><2
} :b.3CL\.6
for(int i=0;i<nEndPos.length-1;i++) a:=q8Qy
{ $[)6H7!U)
nEndPos = nStartPos[i+1]; |Uc<;> l
} X";TZk
nEndPos[nEndPos.length-1] = nFileLength; "w>rlsT<O
} tX@0:RX%
} 4 U3C~J
Tw2Xe S
=g/4{IL%
//启动子线程 :8](&B68gE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -K:yU4V
for(int i=0;i<nStartPos.length;i++) Y=AH%Gy9)
{ >/(i3)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AqKHjCI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -b@v0%Q2M*
nStartPos,nEndPos,i); E7V38Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MomLda V9Q
fileSplitterFetch.start(); k}- "0>
} mfj4`3:NV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lq;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /7c2OI=\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mk#>Dpy?
nEndPos = " + nFileLength); r3n=<l!Jr
// fileSplitterFetch[nPos.length-1].start(); UAnB=L,.\
fn4=
~C%2t{"
//等待子线程结束 f+*J ue
//int count = 0; Rbx97(wK
//是否结束while循环 QIR4<]/
boolean breakWhile = false; U* -% M
`2Wl
>L#];|
while(!bStop) aeEw#
{ OG0r4^6Ly
write_nPos(); ^RYn8I
Utility.sleep(500); lF0K=L
breakWhile = true; d\v$%0
elN{7:
9yh9HE
for(int i=0;i<nStartPos.length;i++) suA+8}o]
{ :({-0&&_
if(!fileSplitterFetch.bDownOver) Ll008.#
{ r~8D\_=s
breakWhile = false; N!tpzHXw
break; jjJc1p0
} @WhZx*1
} *jYHd#UZx4
if(breakWhile) k)?,xY\AV
break; <9Lv4`]GU5
O<}ep)mr
r~ZS1Tp
//count++; b=6MFPbg
//if(count>4) SZCF3m&pz
// siteStop(); LEYWH%y
} %1Vu=zCAW
!7ei1
( rA\_FOJ
System.err.println("文件下载结束！"); Mfnlue](
} OpWeW
catch(Exception e){e.printStackTrace ();} J xA^DH
} UN cYu9[
xI=}z
AZh@t?)
//获得文件长度 utYnaeQcn
public long getFileSize() P5'iYahCq_
{ 6Cz7A
int nFileLength = -1; t/l!KdY$
try{ FY1},sq
URL url = new URL(siteInfoBean.getSSiteURL()); sN}s61
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <'PR;g^#
httpConnection.setRequestProperty("User-Agent","NetFox"); 2rK-X_}
h Jfa_
o|R*POM
int responseCode=httpConnection.getResponseCode(); "Y"t2l_n
if(responseCode>=400) FK4nz2&4
{ '5|Q<5!o
processErrorCode(responseCode); CL)1Q
return -2; //-2 represent access is error Ss"|1]acP
} &"U9X"8b
zWCW:dI
V_)5Af3wY
String sHeader; ^CowJ(y(
}-REBrb-
-/(DPx
for(int i=1;;i++) !Iw{Y'
{ c!'A)JD@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )GiFkG
//Utility.log(in.readLine()); p)?qJ2c|
sHeader=httpConnection.getHeaderFieldKey(i); K7t&fDI
if(sHeader!=null) mF6@Y[/B
{ *G%1_
if(sHeader.equals("Content-Length")) (SgEt
{ %JP&ox|^&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /0B07B
break; no~OR Q
} 4kW30Ma
} wx]+*Lzz
else c,#~L7
break; J~_L4*Jw
} }m=tzHB*
} 9[epr+f
catch(IOException e){e.printStackTrace ();} Jcwh|w9D8
catch(Exception e){e.printStackTrace ();} Zu2m%=J`
9IS1.3
@{J!6YGh
Utility.log(nFileLength); x&hvFG3
Hrd5p+j
{ 4_I7r
return nFileLength; d-6sC@PB
} ,wwU` U
..P=D <'f
Zd[y+$>
//保存下载信息（文件指针位置） 2.fyP"P L
private void write_nPos() TIK/%T
{ A%NK0j$;}
try{ `l[6rf_.
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1S*8v7
output.writeInt(nStartPos.length); "4Vi=*2V
for(int i=0;i<nStartPos.length;i++) p6&LZ=tL3
{ htUy2v#V
// output.writeLong(nPos); h/0<:eZ*
output.writeLong(fileSplitterFetch.nStartPos); J)7,&Gc6
output.writeLong(fileSplitterFetch.nEndPos); p=8M0k
} I2t-D1X
output.close(); p\\P50(-
} EuKrYY]g
catch(IOException e){e.printStackTrace ();} ;#5-.z
catch(Exception e){e.printStackTrace ();} UA69_E{JCH
} )#b}qc#`
_/QKWk&j
*([0"
//读取保存的下载信息（文件指针位置） boC>N
private void read_nPos() h3UZ|B0=
{ 'NQMZfz
try{ p?Z+z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %:'1_@Ot2
int nCount = input.readInt(); @!L@UP0
nStartPos = new long[nCount]; t7C!}'g&'
nEndPos = new long[nCount]; 4*N@=v
for(int i=0;i<nStartPos.length;i++) [3{:H"t
{ /?.r!Cp
nStartPos = input.readLong(); _H^^2#wc/
nEndPos = input.readLong(); HobGl0<y
} N[+o[%A
input.close(); |?;"B:0
} ohQz%?r
catch(IOException e){e.printStackTrace ();} YO.`l~ v
catch(Exception e){e.printStackTrace ();} Y5h)l<P>B
} ]HNT(w@
F- !}dzO
*7xQp!w^
private void processErrorCode(int nErrorCode) )9A<fwpN
{ fw(j6:p
System.err.println("Error Code : " + nErrorCode); MYDf`0{$_a
} jt'Y(u]2
S+_A <p
4t+/
//停止文件下载 O)$N}V0
public void siteStop() WQIM2_=M
{ tKs4}vW
bStop = true; eu}:Wg2
for(int i=0;i<nStartPos.length;i++) i h`y0(<
fileSplitterFetch.splitterStop(); Pjj;.c 7_j
Pq{YZMr
26('V `N
} evndw>
} ^huBqEs
//负责部分文件的抓取 ^V XXq
**FileSplitterFetch.java n7`.<*:
*/ "EOk^1,y
package NetFox; eSvc/CU
~u?x{[
:r vO8.\
import java.io.*; z/P^-N>
import java.net.*; A_6/umF[ZA
FM;;x(sg
0f=N3)
public class FileSplitterFetch extends Thread { NSiYUAug
6bRQL}[
k<j)?_=`
String sURL; //File URL T|BY00Sz`
long nStartPos; //File Snippet Start Position *mK);@pL
long nEndPos; //File Snippet End Position *s<dgFA'
int nThreadID; //Thread's ID Vne.HFXA
boolean bDownOver = false; //Downing is over 72s$
boolean bStop = false; //Stop identical %Zl_{Q]h
FileAccessI fileAccessI = null; //File Access interface fUL{c,7xda
U"%8"G0)
35@Ibe~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e%@[d<Ta\
{ 4s1kZ`e
this.sURL = sURL; M$>WmG1~D
this.nStartPos = nStart; 1^WA
this.nEndPos = nEnd; &t.>^7ELF
nThreadID = id; 8&2gM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0()9vTY+
} Skk3M?
VvMU)
tI!R5q;k
public void run() bb O;AiHD
{ 6>N u=~
while(nStartPos < nEndPos && !bStop) 93Ci$#<y
{ ,39$iHk
zhR_qW+
x9&tlKKxf
try{ *Y^Y
URL url = new URL(sURL); *\~kjZ 3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 66"ZH,335
httpConnection.setRequestProperty("User-Agent","NetFox"); {C0OrO2:
String sProperty = "bytes="+nStartPos+"-"; j_ywG{Jk
httpConnection.setRequestProperty("RANGE",sProperty); 2fL88/'
Utility.log(sProperty); I8-&.RE
k+m_L{#m5
*>&N t
InputStream input = httpConnection.getInputStream(); w_z^5\u0
//logResponseHead(httpConnection); bbPd&7
i_ODgc`H
1Z$99
byte[] b = new byte[1024]; =|{,5="
int nRead; w3?t})PB&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Kz*AzB
{ }&C!^v o
nStartPos += fileAccessI.write(b,0,nRead); HU'`kimWb
//if(nThreadID == 1) [%)B%h`XGf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KbuGf$Bv
} gx>mKSzy
#35S7G^@`
BI]ut|Qw
Utility.log("Thread " + nThreadID + " is over!"); ~cg+BAfu
bDownOver = true; W*/s4 N
//nPos = fileAccessI.write (b,0,nRead); ?BWvF]p5/
} _^2[(<Gmv
catch(Exception e){e.printStackTrace ();} $85o%siS'
} [>]VN)_J5
} u2.r,<rC*Q
2S10j%EeI
@Qsg.9N3K
//打印回应的头信息 &40JN}
public void logResponseHead(HttpURLConnection con) G'}_ZUy#
{ &LxzAL,3!
for(int i=1;;i++) /jL{JF>I
{ RVKaqJ0e<
String header=con.getHeaderFieldKey(i); ^%OH}Z`ly
if(header!=null) K/.hJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X)R]a]1A
Utility.log(header+" : "+con.getHeaderField(header)); r`E1<aCr|
else 4oaP"T@6
break; {ZIFj.2
} Mp@(/
} ,E8>:-boL
Y"\T*lKa
9q@YE_ji
public void splitterStop() (XIq?c1T
{ fvBC9^3
bStop = true; zl8\jP
} ?28GQyk4
>dC(~j{
b%~3+c
} ZT-45_
VflPNzixb!
b+j_EA_b
/* m&z%kVsg]
**FileAccess.java 7;s0m0<%~
*//文件访问(定位，写) :)V0zHo&(
package NetFox; au}0PnA;
import java.io.*; u$/2XO
ib=^tK
@U.}Ei
public class FileAccessI implements Serializable{ m=l3O:~J
tlxjs]{0E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kd4*Zab
RandomAccessFile oSavedFile; +n~rM'^4/
long nPos; 9M~$W-5
Pg8=
8}`8lOE7
public FileAccessI() throws IOException .Fz6+m;Z
{ G.E~&{5xQ
this("",0); Hf]}OvT>Z
} AA%g^PWpR
S@2Jj>3D?
NeZYchR
public FileAccessI(String sName,long nPos) throws IOException F4{. 7BT
{ 7ofH@U
oSavedFile = new RandomAccessFile(sName,"rw"); \^W?
this.nPos = nPos; (']z\4o
oSavedFile.seek(nPos); exN#!&;
} oW1olmpp=
D~?*Xv]s~
n[S*gX0
public synchronized int write(byte[] b,int nStart,int nLen) 7XC}C+
{ pQ`L=#WM
int n = -1; >;U%~yy}qc
try{ q9z!g/,d/
oSavedFile.write(b,nStart,nLen); zyn =Xv@p
n = nLen; B-p5;h>
} =<uz'\Ytv%
catch(IOException e) 90696v.
{ GIl{wd
e.printStackTrace (); f!Nc+
} ;HwJw\fo
T ]nR XW$
Vw@x
return n; 8r|
} :H:}t>X6Vo
5{f/H] P
zw:b7B]
} zYJ`.,#C 5
a9JJuSRC
Vk=<,<BB
/* Vx8.FNJh
**SiteInfoBean.java KEB>}_[
*/ /FZ )ej\
package NetFox; j|8{Vyqd
7uH{UpslJ
nE$ V<Co}
public class SiteInfoBean { d"uM7PMs7x
05zdy-Fb
|}Z"|-Z
private String sSiteURL; //Site's URL znpZ0O\!
private String sFilePath; //Saved File's Path zq>"a&Y,
private String sFileName; //Saved File's Name g[)hm`{?
private int nSplitter; //Count of Splited Downloading File 5W'|qmJ
WZ-{K"56
Ybiz]1d
public SiteInfoBean() A^7Zy79
{//nSplitter的缺省值为5 `erQp0fBM
//default value of nSplitter is 5 .f<,H+m^
this("","","",5); /P}tgcs
} :iiTz$yk
bvvx(?!
ptfADG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) itMc!bUQ
{ G2k71{jK
sSiteURL= sURL; 8j+;Xlh
sFilePath = sPath; Rzj!~`&N
sFileName = sName; {]N?DmF
this.nSplitter = nSpiltter; [NDYJ'VGe
3+PM_c)Y
OtqLigt&l
} \K=PIcH
IUG.q8
Efd[ZJxS6
public String getSSiteURL() `G{t<7[[;
{ ~/[N)RFD
return sSiteURL; ds[~Cp
} A|nU _*
-<.NEV
}+3~y'k
public void setSSiteURL(String value) 2Rt ZTn
{ @3D%i#2o&[
sSiteURL = value; zOp"n\
} (jMp`4P
CBHWMetJ*
Ghe=hhZ
public String getSFilePath() (acRYv(
{ 8\_,Y ji
return sFilePath; I9aber1
} l,8|E
wpmtv325
J(L$pIM
public void setSFilePath(String value) p 1fnuN |,
{ 3P>@ :
sFilePath = value; Dn!V)T
} Fm{y.URo
|mX8fRh
pswppC6f
public String getSFileName() $nN$"
{ }e w?{
return sFileName; _"TG:RP
} =]Bm>67"
=^}2 /vA
u^9,u/gj
public void setSFileName(String value) 81g0oVv
{ vsR&1hs
sFileName = value; CjCnh7tm
} W5 }zJ)x
}])f^
OMNdvrE*=O
public int getNSplitter() o!&*4>tF
{ )A"7l7?.n)
return nSplitter; :W55JD'
} BJTljg({o
N9Vcp~;
A&#Bf#!G
public void setNSplitter(int nCount) KcE=m\h
{ z""(M4
nSplitter = nCount; !b_IH0]U
} _l<"Qqt
} =cY]cPO
`WL*Jb
a WC sLH
/* F!'"mU<f
**Utility.java mZ%\`H+
*/ l0V@19Ec
package NetFox; N*;/~bt7P
H(|v
\zU R9h
public class Utility { Nq8A vBwo4
z'*>Tk8h
sa])^mkq(
public Utility() ([A;~ p;n
{ _9dV 3I
p-_j0zv
u^$ CR
} G})mw
*{bqHMd4L
//线程睡眠 $6[]c)(
public static void sleep(int nSecond) 'AU!xG6OQ
{ `Hqu2 '`
try{ %|~UNP$
Thread.sleep(nSecond); Y,r2m nq
} A_+WY|#M
catch(Exception e) X5=7DE]
{ O)?0G$0
e.printStackTrace (); >'eqOZM
} 78"W ~`8
} VrG|/2
!.A>)+AK
//日志 g$qh(Z_s
public static void log(String sMsg) nK[$ID
{ -=Hr|AhE
System.err.println(sMsg); +( d2hSIF
} Phczf
f.{0P-Np
>=(e}~5y
public static void log(int sMsg) +oa]v1/W
{ &DV'%h>i=
System.err.println(sMsg); 9cQSS'`F
} {rDZKy^f
} uo^>95lkv
)_ y{^kn3^
Vl%k:
/* aap:~F{]X
**TestMethod.java i8]r}a
*/ !WmpnPr1
package NetFox; -MZ Eli g
pJIH_H
"#()4.9
public class TestMethod { ^/,s$dj
Us<lWEX;k
XN Y(@
public TestMethod() *HVO
{ ///xx/weblogic60b2_win.exe {+ m)*3~w
try{ K:0RP?L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UkC\[$-"\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cjL!$OE6
SiteFileFetch fileFetch = new SiteFileFetch(bean); j8b:+io
fileFetch.start(); Cn,dr4J[
} t t=$:}A
catch(Exception e){e.printStackTrace ();} t%%I.zIV7
`u-}E9{
n\ZFPXP
} 5"sF#Y&
ifkA3]
` mi!"pmw
public static void main(String[] args) m-:k]9I
{ Oj2[(7mO/
new TestMethod(); TCYnErqk
} +1Uw<~
} !(]|!F[m
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