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)); ETm:KbS
} ~g}blv0q+B
for(int i=0;i<nEndPos.length-1;i++) lXRB"z
{ MM*9Q`cB
nEndPos = nStartPos[i+1]; E <N%
} T>irW(
nEndPos[nEndPos.length-1] = nFileLength; cv_t2m
} : cPV08i
} W/.n R[!
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//启动子线程 m A('MS2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; blUS6"kV}
for(int i=0;i<nStartPos.length;i++) 3uL$+F
{ 5&_R+g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "iJAM`Hi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $S^rKp#
nStartPos,nEndPos,i); LhSXz>AX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c~={A
fileSplitterFetch.start(); D7Y?$=0ycb
} 69 J4p=c,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I:WPP'L4o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a1x].{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v8TNBsEL
nEndPos = " + nFileLength); v}=pxWhm
// fileSplitterFetch[nPos.length-1].start(); k>=wwPy
>:OP+Vc
AMN`bgxW
//等待子线程结束 _ucixM#
//int count = 0; ZU`HaL$
//是否结束while循环 I7C+XUQkQ
boolean breakWhile = false; ,=2)1I]
dKmPKeJM
rIX 40,`
while(!bStop) !Pu7%nV.
{ \==Mgy2J8
write_nPos(); r;O?`~2'4
Utility.sleep(500); M"foP@
breakWhile = true; Pr,C)uch
_MTvNs
q)PSHr=Z
for(int i=0;i<nStartPos.length;i++) 2<*Yq8
{ mhF@S@
if(!fileSplitterFetch.bDownOver) _)~|Z~
{ xR;z!Tg)
breakWhile = false; u1|v3/Q-
break; qc3?Aplj
} W+.?J 60
} PPh1y;D
if(breakWhile) a?)g>e HN
break; kdMB.~(K=
{"0n^!
!v*#E{r"g=
//count++; Is97>aid
//if(count>4) UJ`%uLR~
// siteStop(); sA }X)aP
} V/)3d
/x/W>J2
:~p_(rE
System.err.println("文件下载结束！"); 6wb M$|yFj
} nTsPX Tat
catch(Exception e){e.printStackTrace ();} 3]>YBbXvE
} nZ`=Up p)
z.W1Za
7KtgR=-Lb
//获得文件长度 4-\4G"4
public long getFileSize() +EZr@
{ we?t/YB=
int nFileLength = -1; QzYaxNGv
try{ eXdH)|l,\
URL url = new URL(siteInfoBean.getSSiteURL()); r<*Y1;7H'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UHDcheeRD
httpConnection.setRequestProperty("User-Agent","NetFox"); +PO& z!F
tOPkx(
7VJf~\%1j
int responseCode=httpConnection.getResponseCode(); obw:@i#
if(responseCode>=400) U27ja|W^
{ wDs#1`uTq
processErrorCode(responseCode); ~'):1}KN]
return -2; //-2 represent access is error 'v@1_HHW\
} ;e~K<vMm;y
5a* Awv}
.\)p3pC)
String sHeader; FFH{#|_1
jw]IpGTt
,aa %{
for(int i=1;;i++) i{PX=
{ ]o_E]5"jO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v=H!Y";
//Utility.log(in.readLine()); 87nsWBe
sHeader=httpConnection.getHeaderFieldKey(i); CzT_$v_
if(sHeader!=null) Vb2")+*:
{ (7v`5|'0
if(sHeader.equals("Content-Length")) ;"%luQA<w
{ B^1Io9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GF Rd:e
break; _j<,qi
} ,qlFk|A|
} ? oGmGKq
else EtB56FU\
break; Sq2yQSd
} iainl@3Qj
} uMP&.Y(
catch(IOException e){e.printStackTrace ();} L^nS%lm
catch(Exception e){e.printStackTrace ();} X .S8vlb4z
$Vm J[EF1
3K_!:[
Utility.log(nFileLength); %P]-wBJw
QLTE`t5w3'
ZP%Bu2xd
return nFileLength; WTh|7&
} ?/s=E+
q}5&B=2pM
PiIILX{DuH
//保存下载信息（文件指针位置） /XW,H0pR
private void write_nPos() 2qkC{klC^M
{ 4U:+iumy2
try{ Y'%_--
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^F1zkIE
output.writeInt(nStartPos.length); :Ee5:S
for(int i=0;i<nStartPos.length;i++) fKT(.VNq5
{ /t?(IcP5
// output.writeLong(nPos); @i:_JOl
output.writeLong(fileSplitterFetch.nStartPos); on1mu't_;
output.writeLong(fileSplitterFetch.nEndPos); m;I;{+"u
} |&%l @X6
output.close(); %u|qAF2uS
} ~LzTqMHM
catch(IOException e){e.printStackTrace ();} k)USLA
catch(Exception e){e.printStackTrace ();} r,dxW5v.
} 8%#uZG\}
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Jh:-<xy)
//读取保存的下载信息（文件指针位置） 3'2}F%!Mv
private void read_nPos() 1')/BM2
{ s/'gl
try{ _'oy C(:}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <`m.Vbvm"
int nCount = input.readInt(); dUJNr_
nStartPos = new long[nCount]; `+/[0B=.
nEndPos = new long[nCount]; h Tn^:%(
for(int i=0;i<nStartPos.length;i++) B[MZPv)
{ Bj7\{x,?
nStartPos = input.readLong(); >heih%Ar0J
nEndPos = input.readLong(); z*>CP
} JGD{cr[S
input.close(); f1>^kl3@P
} XsHl%o8,z
catch(IOException e){e.printStackTrace ();} w02HSQ
catch(Exception e){e.printStackTrace ();} (;h]'I@
} ^ihXM]1{G
9tC8|~Q
`ionMTZY
private void processErrorCode(int nErrorCode) P-`^I`r
{ osX23T~-
System.err.println("Error Code : " + nErrorCode); _.06^5o
} F]?$Q'U
@kwD$%*0
7"JU)@ U]
//停止文件下载 6YU2 !x
public void siteStop() C5RDP~au
{ LDvF)Eg
bStop = true; Lou4M
for(int i=0;i<nStartPos.length;i++) JnY3]
fileSplitterFetch.splitterStop(); AQ 7e
^! ZjK-$A<
cuk2\> Xl
} Nd!2 @?V4
} KwQO,($,]
//负责部分文件的抓取 )SUN+YV^
**FileSplitterFetch.java nZ7v9o9
*/ M7Hk54U+t
package NetFox; 5\Y/so=
0_D~n0rq,v
6l vx
import java.io.*; e#HP+b$
import java.net.*; [Iihk5TT
L kq>>?T=
(Fgt#H(B
public class FileSplitterFetch extends Thread { Jp-ae0 Ewa
X)f"`$
kdYl>M
String sURL; //File URL q=1SP@;\6
long nStartPos; //File Snippet Start Position MthThsr7
long nEndPos; //File Snippet End Position -6tF
int nThreadID; //Thread's ID x(7K3(#|
boolean bDownOver = false; //Downing is over C aJD*
boolean bStop = false; //Stop identical o"1us75P
FileAccessI fileAccessI = null; //File Access interface }lb.3fqiA
#Aanv
5PL,~Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n ~3c<{coZ
{ YKc{P"'/|
this.sURL = sURL; \!V6` @0KC
this.nStartPos = nStart; }\*Sf[EMD
this.nEndPos = nEnd; rzBWk
nThreadID = id; !3&vgvr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1aT$07G0
} d|NNIf
"DN`@
`(a^=e5
public void run() U;q)01
{ 5~"=Fm<uD
while(nStartPos < nEndPos && !bStop) zm.2L
{ sk3;;<H
0?h .X=G
J;kbY9e
try{ jw[`_
URL url = new URL(sURL); 7=AKQ7BB>b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vZDQ@\HrC
httpConnection.setRequestProperty("User-Agent","NetFox"); `cv:p|s
String sProperty = "bytes="+nStartPos+"-"; 5UM[Iz
httpConnection.setRequestProperty("RANGE",sProperty); 5,((JxX$
Utility.log(sProperty); 5k(#kyP
68!fcK
E0pQRGPA
InputStream input = httpConnection.getInputStream(); t]o gn(
//logResponseHead(httpConnection); l&A`
E>1USKxn
UK<"|2^sT
byte[] b = new byte[1024]; "}EbA3
int nRead; f\^QV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WE7l[<b
{ 7@"X~C
nStartPos += fileAccessI.write(b,0,nRead); g0U ?s
//if(nThreadID == 1) z} \9/`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <FK><aA_i*
} W%W. +f
QaO`:wJj
DRIv<=Bt
Utility.log("Thread " + nThreadID + " is over!"); R`&ioRWj
bDownOver = true; J?<L8;$s7
//nPos = fileAccessI.write (b,0,nRead); u~kwNN9t3
} 4dK@UN\
catch(Exception e){e.printStackTrace ();} K]oPh:E
} ] 6gu
} F1=+<]!
v8IL[g6"
Z9D4;1
//打印回应的头信息 vSA%A47G
public void logResponseHead(HttpURLConnection con) 8#Z5-",iw
{ /fq6-;co+
for(int i=1;;i++) PS22$_}
{ IXN4?=)I
String header=con.getHeaderFieldKey(i); M5V1j(URE
if(header!=null) g3XAs@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !%X`c94
Utility.log(header+" : "+con.getHeaderField(header)); D+3Y.r9
else aVYUk7_<
break; "p{'984r<
} ;Z_C3/b
} eQx"nl3U%
#c>MUC(?s:
$(R) =4
public void splitterStop() !q/lgpEi
{ [mPdT^h
bStop = true; `[\phv
} ^-!HbbVv
"/fs%F
h;KK6*Z*$E
} S\ZAcz4
z{d5Lrk
wVOL7vh
/* iL, XBoE
**FileAccess.java =R.9"7~2x
*//文件访问(定位，写) ks;wc"k"
package NetFox; 5uer [1A
import java.io.*; jZ!JXmVV
eLny-.i,7
R6XMBYK^
public class FileAccessI implements Serializable{ y^\#bpq&\
@RIEO%S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c1J)yv1y
RandomAccessFile oSavedFile; h$k3MhYDes
long nPos; =.hDf<U
9VE;I:NO3
H@ms43v\
public FileAccessI() throws IOException Ekme62Q>u
{ X^5"7phI@
this("",0); &'b}N
} l%(`<a]VIB
\ZRoTh
~N^vE;
public FileAccessI(String sName,long nPos) throws IOException 1qe^rz|
{ %UQB?dkf$
oSavedFile = new RandomAccessFile(sName,"rw"); 'kvFU_)
this.nPos = nPos; N-9gfG
oSavedFile.seek(nPos); ^&H=dYcV>/
} A'1AU:d
R?~h7 d
\]A;EwC4C
public synchronized int write(byte[] b,int nStart,int nLen) _vV&4>
{ vqOLSE"t*O
int n = -1; M%s$F@
try{ ~vV)|
oSavedFile.write(b,nStart,nLen); [?@wCY4=
n = nLen; BkxhF
} ,nR8l
catch(IOException e) D(6x'</>?
{ }~r6>7I
e.printStackTrace (); X,+}syK
} j(C UYm
KR(} A"
V?59.TJ
return n; uyt-q|83=
} :wZ`>,K"t>
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chmJ|
} j& iL5J;
i:M*L< +
.00=U;H%`
/* Jav2A6a
**SiteInfoBean.java ]}7rWs[|1
*/ pEj^x[b`^
package NetFox; 7b,,%rUd
6//FZ:q
7E3SvC|M
public class SiteInfoBean { qf`xH"$
p <=%
!NLvo_[Y
private String sSiteURL; //Site's URL 0nn]]B@l
private String sFilePath; //Saved File's Path yCCw<?
private String sFileName; //Saved File's Name 2{B(j&{
private int nSplitter; //Count of Splited Downloading File ]p&<nK,
Jrd4a~XP
prEu9$:t
public SiteInfoBean() CQzjCRS d
{//nSplitter的缺省值为5 E<CxKY9
//default value of nSplitter is 5 mzE$aFu8
this("","","",5); Mq:'-`
} /;NE]{K
Bd9hf`%2
%7>AcTN~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3V Mh)
{ afF+*\xXN
sSiteURL= sURL; bV$8 >[`
sFilePath = sPath; 3$N %iE6
sFileName = sName; ^jha:d
this.nSplitter = nSpiltter; 9c^skNbS
,3]?%t0xe
D<bU~Gd,P
} .D,?u"fk|
hK39_A-
;eW'}&|LV
public String getSSiteURL() =Etwa
{ |5~wwL@LW7
return sSiteURL; y,v0-o~q
} <L/M`(:=k
XK%W^a*x
}or2 $\>m
public void setSSiteURL(String value) e-iYJ?
{ ,V33v<|wc
sSiteURL = value; J7ktfyQ0W
} #5-A&
L)/6kt=
3aO;@GNJ
public String getSFilePath() 'EL ||
{ mC:X4l]5
return sFilePath; A3"1D
} =s0g2Zv"\
pfL2v,]g
r}R^<y@I
public void setSFilePath(String value) dqD;y#/
{ 8K.s@<
sFilePath = value; EvqUNnjR
} i'!jx.
cBab2/
Yz2{LW[K
public String getSFileName() BZJKiiD
{ C!7U<rI
return sFileName; Kd/[Bs%
} Ehb?CnV#J
>HcYVp~G
TwM1M["3
public void setSFileName(String value) ,b6kTQq
{ tg7C;rJ
sFileName = value; NokXE
} U~{Sa+
gb=80s0
N b3I%r
public int getNSplitter() ~>#LOT `
{ Ql~#((K
return nSplitter; _8[UtZYG
} WYwzo V-
_x\-!&[p
VLh%XoQx[
public void setNSplitter(int nCount) rWoe ?g
{ #Rin*HL##
nSplitter = nCount; /B,B4JI)/
} 7szls71/=
} j`2B}@2
K08 iPIkQ
Cq?',QU6j
/* v78&[
**Utility.java a3O nW\N
*/ fDU+3b
package NetFox; j:HH#U
A$7Eo`Of
7<EJo$-j
public class Utility { <ZigCo w
M[h1>}$Lz
,^.S0;D,Z
public Utility() 5U0ytDZ2/(
{ '"` Lv/
968Ac}OA
4)c+t"h
} IIq"e~"Vs
')C|`(hs
//线程睡眠 LKqRvPnh
public static void sleep(int nSecond) cJP'ShnCh
{ `aO.=:O_
try{ <9@&oN+T
Thread.sleep(nSecond); "0|BoG
} m9#}X_&x
catch(Exception e) X,>(Y8
{ U:qF/%w
e.printStackTrace (); ^pJ0nY#c
} {B@*DQv
} |.j^G2x
mYjf5
//日志 5\VxXiy0
public static void log(String sMsg) %z1{Kus
{ 65lOX$*{-
System.err.println(sMsg); pz$_W
} -{!&/;Z
pAENXC\,
mH'\:oN
public static void log(int sMsg) =fo4x|{O
{ G-2EQ.
System.err.println(sMsg); DZJeup?Z
} (F_w>w.h
} 6/|U
c2/FHI0J;
wOjv[@d
/* DWuRJ
**TestMethod.java {U(Bfe^a,
*/ 8,=G1c
package NetFox; =Wj{]&`
O-Dc[t%
gyC^K3}
public class TestMethod { otU@X 3<_
_]P a>8X*
_=uviMuE
public TestMethod() %=BtOM_2
{ ///xx/weblogic60b2_win.exe . /Y&\<
try{ s}jlS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :#Ty^-"]1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B-$+UE>%
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0"TgLd
fileFetch.start(); Y7-*2"!
} NP "ylMr7P
catch(Exception e){e.printStackTrace ();} 6?O}Q7G
L4~ W/6A
$cq!RgRn
} 'X54dXS?l
}0Y`|H\v
NJ<N%hcjK
public static void main(String[] args) `y'aH 'EEd
{ ):S!Nl
new TestMethod(); au}s=ua~i
} Ym'7vW#~
} F,zG;_
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