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)); yU@~UCmja
} ?$T39U^
for(int i=0;i<nEndPos.length-1;i++) &MlBpI
{ <.h\%&'U
nEndPos = nStartPos[i+1]; i;Y@>-[e<
} Fc"&lk4e
nEndPos[nEndPos.length-1] = nFileLength; *!gj$GK@%
} -Jtx9P
} 6^DsI
;I+"MY7D
{vJ)!'Eh
//启动子线程 _>moza
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bw[jrK
for(int i=0;i<nStartPos.length;i++) l?/.uNw
{ iC{~~W6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %ycCNS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :~2An-V
nStartPos,nEndPos,i); kH43 T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [?$|
fileSplitterFetch.start(); Gkr^uXNg#
} f2#9E+IQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R "&(Ae?LR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /Lc= K<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2z\4?HJy
nEndPos = " + nFileLength); 7Pc0|Z/
// fileSplitterFetch[nPos.length-1].start(); N&0MA
Vd{h|=J
IFX|"3[$
//等待子线程结束 ] _/d
//int count = 0; m7XJe[O
//是否结束while循环 Qjj:r~l
boolean breakWhile = false; Qn7l-:`?
|m%M$^sZ}
&E{5k{Y
while(!bStop) 6rnehv!p
{ @x@w<e%
write_nPos(); PSdH9ea
Utility.sleep(500); JL9d&7-
breakWhile = true; lbES9o5
O^]I>A#d
X'&$wQ6,K
for(int i=0;i<nStartPos.length;i++) TgaDzF,j{A
{ 3"gifE
if(!fileSplitterFetch.bDownOver) )r2$/QF9
{ {}3kla{
breakWhile = false; /)i)wxi
break; T$]2U>=<J
} {I|k@
} 8i;N|:WdH
if(breakWhile) v}IP%84
break; I_yIVw;
r<oI4px
6bg+U`&g
//count++; dv0TJ 0%
//if(count>4) 0;)6ZU
// siteStop(); |zu>G9m
} 7[-jr;v
v.1= TBh
xLZQ\2q
System.err.println("文件下载结束！"); lxK_+fj q
} g[;iVX^1&
catch(Exception e){e.printStackTrace ();} \2<2&=h?
} ISr~JQr
r1FE$R~C=
5Ag>,>kJ6
//获得文件长度 Xl6)&
public long getFileSize() Q:~w;I
{ @2_s;!K
int nFileLength = -1; <LW|m7
try{ $Yz &x%Lb
URL url = new URL(siteInfoBean.getSSiteURL()); HHZ!mYr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2H<?
httpConnection.setRequestProperty("User-Agent","NetFox"); Xh]\q)
b,a\`%m}
vc2xAAQ
int responseCode=httpConnection.getResponseCode(); yT&bS\
if(responseCode>=400) .Qh8I+Q%
{ ^BM/K&7^
processErrorCode(responseCode); %:o@IRTRU
return -2; //-2 represent access is error +^+wS`Y
} x#0C+cU
[6S"iNiyKT
=] 5;=>(
String sHeader; BHmA*3?
n@L!{zY
l7{hq}@;cC
for(int i=1;;i++) +>qBK}`
{ "tIf$z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); savz>E&
//Utility.log(in.readLine()); FA^x|C=$
sHeader=httpConnection.getHeaderFieldKey(i); ~+7yi4(i
if(sHeader!=null) -e(2?Xq9
{ /&j4IlT
if(sHeader.equals("Content-Length")) Xs?7Whc6
{ ,.FTw,<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &up/`8
break; z%/ww7H
} hqD;<:.
} lO $M6l
else *A\NjXJl~
break; SA>;]6)`(
} xdo{4XY^*W
} ^y6Pkb P
catch(IOException e){e.printStackTrace ();} E2*"~gL^,
catch(Exception e){e.printStackTrace ();} jX&&@zMq
\wRr6-!_
Mty]LMK
Utility.log(nFileLength); GvzPT2E!
8)POEY4
|>3a9]
return nFileLength; x}x@_w
} }2c}y7B,_
>!)VkDAG
P)ZSxU
//保存下载信息（文件指针位置） u F*cS&'Z
private void write_nPos() ex!^&7Q(
{ 4}LF>_+=
try{ z~ u@N9M
output = new DataOutputStream(new FileOutputStream(tmpFile)); !RcAJs'
output.writeInt(nStartPos.length); ,O~2 R
for(int i=0;i<nStartPos.length;i++) C-Fp)Zs{0
{ pO+1?c43
// output.writeLong(nPos); 2FVKgyV
output.writeLong(fileSplitterFetch.nStartPos); h5F'eur
output.writeLong(fileSplitterFetch.nEndPos); }ZmdX^xB
} Y|VzeJC
output.close(); 1M;)$m:
} .sG,TLE[<
catch(IOException e){e.printStackTrace ();} ONjc},_
catch(Exception e){e.printStackTrace ();} O[L8(+Sn
} '6 'XBL?
>Au<y,Tw
>A,WXzAK}S
//读取保存的下载信息（文件指针位置） 3N*Shzusbt
private void read_nPos() G>RYQ{O
{ C(0Iv[~y/
try{ 17i^|&J6}:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *Yr-:s9J9
int nCount = input.readInt(); xY'g7<})$
nStartPos = new long[nCount]; ,xh9,EpBk
nEndPos = new long[nCount]; &vF"I'V
for(int i=0;i<nStartPos.length;i++) )(L&+DDy
{ <@vE3v;
nStartPos = input.readLong(); ;ZqFrHI M`
nEndPos = input.readLong(); AX,Db%`l,
} tJu<#hX
input.close(); sMS`-,37u
} "G,*Z0V5
catch(IOException e){e.printStackTrace ();} |wb7`6g
catch(Exception e){e.printStackTrace ();} |fI%L9
} 7.Mh$?;i9
/*O,T
;&!dD6N
private void processErrorCode(int nErrorCode) #] GM#.
{ UKJY.W!w4
System.err.println("Error Code : " + nErrorCode); Q]7Q
} \fKE~61
`P5"5N\h
.~U9*5d
//停止文件下载 l46F3C|
public void siteStop() 0/gcSW b
{ ;?o C=c
bStop = true; *=7[Ip<X
for(int i=0;i<nStartPos.length;i++) ~/x42|t
fileSplitterFetch.splitterStop(); $"FdS,*qKl
H\k5B_3OU
>eTlew<5
} CbHNb~
} <M7*N.
//负责部分文件的抓取 j%}Jl
**FileSplitterFetch.java xKr,XZu
*/ `SwnKg
package NetFox; 0&\Aw'21
E nvs[YZe
9>#|~P&FE
import java.io.*; _)l %-*Z7p
import java.net.*; biG9?
84[^#ke
r9Z/y*q
public class FileSplitterFetch extends Thread { 19.cf3Dh
$;CC lzw
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String sURL; //File URL ZH(.|NaH
long nStartPos; //File Snippet Start Position 1;P\mff3Y
long nEndPos; //File Snippet End Position LbR-uc?x
int nThreadID; //Thread's ID WNb$2q=
boolean bDownOver = false; //Downing is over RrHnDO'
boolean bStop = false; //Stop identical +o
FileAccessI fileAccessI = null; //File Access interface vOK;l0%
UYQ$c }Z5
Pp/{keEye
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !-c*lb
{ AVr!e
this.sURL = sURL; jVINc=o
this.nStartPos = nStart; rxK0<pWJhx
this.nEndPos = nEnd; (OqJet2{+
nThreadID = id; QC4T=E]`j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [j?<9
} gHx-m2N
HUC2RM?FN
cWc)sb
public void run() $P(nh'\
{ #FB>}:L{h*
while(nStartPos < nEndPos && !bStop) vVYduvw
{ V8yX7yx
pNlisS
^JtHTLHL=
try{ 5 DB>zou
URL url = new URL(sURL); WO-WoPO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^eW.hNg
httpConnection.setRequestProperty("User-Agent","NetFox"); ]uvbQ.l_t
String sProperty = "bytes="+nStartPos+"-"; >t2b?(h/x
httpConnection.setRequestProperty("RANGE",sProperty); 4c=kT@=jX
Utility.log(sProperty); (@E#O$'
{{3H\ rR
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InputStream input = httpConnection.getInputStream(); g8+,wSE
//logResponseHead(httpConnection); zb/Xfu.)?6
@(c<av?
@S7=6RKa[
byte[] b = new byte[1024]; H040-Q;S'
int nRead; =BS'oBn^6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XQOprIJ U
{ F?} *ovy
nStartPos += fileAccessI.write(b,0,nRead); udGGDH
//if(nThreadID == 1) zt2-w/[Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }qv-lO
} XyphQ}\u
E ZKz-}
? SP7vQ/
Utility.log("Thread " + nThreadID + " is over!"); 9Nu#&_2R
bDownOver = true; Q)BoWd
//nPos = fileAccessI.write (b,0,nRead); j dhml%pAd
} G=cH61
catch(Exception e){e.printStackTrace ();} Ro]IE|Fv
} %"Q!5qH&
} iwJ-<v_:h
|u;BAb
/JeqoM"x
//打印回应的头信息 W<91m*
public void logResponseHead(HttpURLConnection con) &PuJV +y
{ 3cO[t\/up
for(int i=1;;i++) +g6j=%
{ )ek 5
String header=con.getHeaderFieldKey(i); aRKRy
if(header!=null) KOEi_9i}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DD 5EHJR
Utility.log(header+" : "+con.getHeaderField(header)); Gu`Vk/&
else **r?
break; k^5Rf
} ""'eTpe
} Y"kS!!C>[
u7zB9iQ&
SE)j}go
public void splitterStop() G=!bM(]R~
{ ;9p5YxD
bStop = true; |akC
} (l8r>V
[l%fL9
/B@%pq
} ~wf~bzs
sq(Ar(L<
m2uML*&O5K
/* 5rA!VES T
**FileAccess.java wu!_BCIy
*//文件访问(定位，写) *<1x:PR
package NetFox; p:<gFZb
import java.io.*; cvV?V\1f
a]Da`$T
uM)9b*Vbo
public class FileAccessI implements Serializable{ n+\Cw`'<H
ICCCCG*[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QGv:h[b_
RandomAccessFile oSavedFile; ~q?"w:@;x
long nPos; G'?f!fz;
7cmr *y
5f&{!N
public FileAccessI() throws IOException , HI%Xn
{ ym*#ZE`B!
this("",0); Y0X94k.u
} W[X!P)=w]
Q`p}X&^a
5@>4)dk\
public FileAccessI(String sName,long nPos) throws IOException *o e0=
{ w4fJ`,
oSavedFile = new RandomAccessFile(sName,"rw"); &PBWJ?@O)r
this.nPos = nPos; D*T$ v
oSavedFile.seek(nPos); wdcryejCkr
} h/0-Mrk;e
lmtQr5U
.A"T086
public synchronized int write(byte[] b,int nStart,int nLen) K~y9zF{
{ TaQ "G
int n = -1; \LoSUl i
try{ w HHF=Q
oSavedFile.write(b,nStart,nLen); QV'3O|
n = nLen; a[P>SqT4`
} F{*9[jY
catch(IOException e) {uwk[f{z
{ $,&gAU
e.printStackTrace (); GkGC4*n
} "Eok;io
"l[V%f E
AY/-j$5+?
return n; Fe&n,
} 9u7n/o&8v6
8A8xY446)
V:G}=~+=
} JM+sHHs
xH`j7qK.
$~G0#JL
/* h*\TCl)
**SiteInfoBean.java ^=izqh5S
*/ 3<)@ll
package NetFox; $E`iqRB
Y6f+__O
APQQ:'>N4~
public class SiteInfoBean { wwK~H
*`g-gk
Z\*5:a]
private String sSiteURL; //Site's URL <^*+8{*
private String sFilePath; //Saved File's Path +6#%P
private String sFileName; //Saved File's Name Mdltzy=)L
private int nSplitter; //Count of Splited Downloading File w*6!?=jP
,p*ntj{
rtYb"-&
public SiteInfoBean() ~E3SC@KL
{//nSplitter的缺省值为5 C:s^s
//default value of nSplitter is 5 x<{;1F,k3
this("","","",5); &w;^m/zP3
} >G4HZE
5}X<(q(
anz9lGG#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N.5KPAvg%
{ V 4\^TO`q=
sSiteURL= sURL; 1%/ NL?8#
sFilePath = sPath; hk"9D<&i>b
sFileName = sName; 2{sD*8&`
this.nSplitter = nSpiltter; m|nL!Wc
J/]o WC`u
CSG+bqUG
} G%j/eTTf
>p]WCb'PH
\sHy.{
public String getSSiteURL() VNr
{ *@ <8&M9x
return sSiteURL; MfNpQ:]c\
} 75\RG+kQ
X]zCTY=l
AT%* ~tr
public void setSSiteURL(String value) As6)_8w
{ + 4V1>e+
sSiteURL = value; =qV4Sje|q
} Wk\mgGn+
`Ct'/h{
;<bj{#mMv
public String getSFilePath() "o^bN 9=
{ nl)_`8=
return sFilePath; "q9~C
} WIEx '{
,u?wYW;
>}dTO/
public void setSFilePath(String value) ]HJ{dcF
{ vDK:v$g
sFilePath = value; S{^6iR
} 0$xK
B91S h`
w&wA >q>&
public String getSFileName() {(m+M
{ ibZt2@GB)I
return sFileName; #sz]PZ\
} 2A*X Hvwb
)Y&MIJ7>@
]^yV`Z8
public void setSFileName(String value) aW`:)y&f
{ ?o(ZTlT
sFileName = value; BB2_J=wA
} njy~
>zPO>.?h7T
K;<NBnH
public int getNSplitter() >u9id>+
{ LPq*ZZK
return nSplitter; ?r -\%_J_(
} N5q}::Odc
u"`5
)CC?vV
public void setNSplitter(int nCount) 5`4}A%@&
{ !p]T6_t]Q
nSplitter = nCount; %|:;Ti
} ;=5@h!@R
} Qa,NGP.
itqQ)\W
GN:Ru|n
/* s jL*I
**Utility.java 763E 6,7
*/ NqiB8hZ~
package NetFox; JwN}Jm
wb(*7 &eP:
nuf@}W>y
public class Utility { Q `e~MD
>:w?qEaE
c8^+^.=pX
public Utility() tyc8{t#Z
{ WW@JVZxK
MxM](ew~7
dIoF~8V
} =8$|_
m.1LxM$8
//线程睡眠 5xh!f%6
public static void sleep(int nSecond) @Ufa-h5"(
{ HBt|}uZ?6i
try{ G"G{AS
Thread.sleep(nSecond); SL[rn<x|
} :wQC_;
catch(Exception e) -rEeKt
{ Zij"/gx\
e.printStackTrace (); 7!O^;]+,
} R<0Fy=z
} R^jlEt\&P
+90u!r^v
//日志 AkxH
public static void log(String sMsg) #=X)Jx~
{ ShC_hi
System.err.println(sMsg); Jy]FrSm^
} :~\LOKf
[NQmL=l
9T8|y]0F
public static void log(int sMsg) ;):8yBMk
{ Qy4X#wgD
System.err.println(sMsg); Ty`-r5
} >pgQb9 T+_
} IkSX\*
e{v,x1Y_z(
L@7Qs6G2u
/* P#AAOSlLV
**TestMethod.java "V:
*/ LiiK3!^i
package NetFox; @''&nRC1
aXRv}WO$>k
/)sDnJ1r
public class TestMethod { * eA{[
zl0;84:H
t[%x}0FP-F
public TestMethod() ^Ku\l #B
{ ///xx/weblogic60b2_win.exe ~RcNZ\2y
try{ EYA/CI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o^6jyb!j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4uFIpS|rq
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3Z_t%J5QZ$
fileFetch.start(); [_j6cj]
} d/l,C4p
catch(Exception e){e.printStackTrace ();} 6,B-:{{e"
?lF mXZy`
\|v`l{
} V@B7P{gH
\s,Iz[0Vfz
7@FDBjq
public static void main(String[] args) Kp8fh-4_
{ )V=0IZi
new TestMethod(); V{43HA10b
} ^gd<lo g
} Po1hq2-U8
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