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)); IG{Me
} f6Lc"b3s1
for(int i=0;i<nEndPos.length-1;i++) G-|c%g!ejf
{ *uf)t,%
nEndPos = nStartPos[i+1]; >;R`Q9s7
} .MRN)p
nEndPos[nEndPos.length-1] = nFileLength; { Ie~MW
} Di27=_J
} )UpVGT)
u[PG/ploc
aXG|IN5 *m
//启动子线程 JM?__b7g2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aG#d41O
for(int i=0;i<nStartPos.length;i++) VzIZT{
{ HY1K(T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1]5k lJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J/E''*
nStartPos,nEndPos,i); Ea][:3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g/ShC8@=u
fileSplitterFetch.start(); 9nY|S{L
} J~4mp\4b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rx 74v!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'DNxc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IVZUB*wv)b
nEndPos = " + nFileLength); @$ Nti>
// fileSplitterFetch[nPos.length-1].start(); <66%(J>
(aC=,5N
j|`lOH8
//等待子线程结束 kX`m( N$
//int count = 0; N*6~$zl&
//是否结束while循环 o|vL:| 8Q
boolean breakWhile = false; .-![ ra
],[<^=|
SZLugyZ2Y
while(!bStop) m@+QC$6S
{ @: =vK?8L
write_nPos(); 8~t8^eBg
Utility.sleep(500); 27+faR
breakWhile = true; 0^nF: F
0Z]HH+Z;
s!
for(int i=0;i<nStartPos.length;i++) &A.0(s
{ lMh>eX
if(!fileSplitterFetch.bDownOver) LyNmn.nN
{ Ok@`<6v
breakWhile = false; E>i<2
break; FG{,l=Z0
} xV`l6QS
} s8 MQ:eAP
if(breakWhile) `-P1Y
break; 1KGf @u%-1
,!alNNY
00f'G2n
//count++; .5!`wwVi
//if(count>4) ,7:-V<'Yv
// siteStop(); ]s^+/8d=
} Vy[xu$y
!.q99DB
}F/w34+;
System.err.println("文件下载结束！"); >B~? }@^Gk
} 53ZbtEwhwr
catch(Exception e){e.printStackTrace ();} <82&F
} e1E_$oJP
F=w:!tqA
kZ)}tA7j
//获得文件长度 WFV'^-4
public long getFileSize() *`wz
{ nw+^@|4
int nFileLength = -1; xP9h$!
try{ p=A,yGDV
URL url = new URL(siteInfoBean.getSSiteURL()); 7RBEEE`)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (3D&GY!/
httpConnection.setRequestProperty("User-Agent","NetFox"); Ab/JCZNn
D}X6I#U'/
wd<{%qK`{
int responseCode=httpConnection.getResponseCode(); g[t paQ
if(responseCode>=400) R) dP=W*
{ r)Lm| S
processErrorCode(responseCode); &fWC-|
return -2; //-2 represent access is error f(blqO.@l
} kSc~gJrne
_izjvg
\xl$z*zI
String sHeader; tJ6Q7 J;n
#}@8(>T
^,^MW
for(int i=1;;i++) DUl+Jqn4B
{ "M-';;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NziCN*6
//Utility.log(in.readLine()); 7=u Gf$/
sHeader=httpConnection.getHeaderFieldKey(i); [)jNy_4
if(sHeader!=null) Ri_2@U-
{ _6,\;"it?8
if(sHeader.equals("Content-Length")) (>ze{T|
{ (7b9irL&cn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F:P2:s<d-
break; rb4;@&
} `o }+2Cb
} PMbZv%.,-
else oOvQAW8`
break; un~`|
} u*I'c2m
} Q8h0.(#-
catch(IOException e){e.printStackTrace ();} =. \hCgq
catch(Exception e){e.printStackTrace ();} %dW;P[0
uQx/o^
T*0;3&sA
Utility.log(nFileLength); 3T0-RP*
fR@Cg sw
%CvVu)tc
return nFileLength; *w _o8!3-
} f sh9-iY8e
lkJxb~S
,K\7y2/
//保存下载信息（文件指针位置） %]0?vw:;j
private void write_nPos() `|Di?4+6%
{ #|Lsi`]+
try{ *'A*!=5(
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'SlZ-SdR
output.writeInt(nStartPos.length); =<Sn&uL
for(int i=0;i<nStartPos.length;i++) 3~3tjhw;]9
{ 9oGcbD4*
// output.writeLong(nPos); sK+uwt
output.writeLong(fileSplitterFetch.nStartPos); 9U.Ctx:F
output.writeLong(fileSplitterFetch.nEndPos); !i (V.A
} fi*b]a\'
output.close(); < B]qqqP
} &QfEDDJ
catch(IOException e){e.printStackTrace ();} ,'`yh|}G\
catch(Exception e){e.printStackTrace ();} 'V:MppQVZ.
} B?-w<":!
KU(BY}/ ^
'5$@I{z
//读取保存的下载信息（文件指针位置） k]r4b`x`
private void read_nPos() C^4,L \E
{ 3fQ`}OcNr
try{ }cCIYt\RK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &Lt$~}*&6
int nCount = input.readInt(); #'>)?]tn
nStartPos = new long[nCount]; Bx5xtJ|!
nEndPos = new long[nCount]; #9[>
for(int i=0;i<nStartPos.length;i++) +3-5\t`
{ X,3\c:
nStartPos = input.readLong(); FA{Q6fi:2
nEndPos = input.readLong(); :X'B K4EN
} 9^n0<(99b
input.close(); ]*k ~jY,
} .4"BN<9
catch(IOException e){e.printStackTrace ();} D>W&#A8&y
catch(Exception e){e.printStackTrace ();} fUWrR1
} JmR2skoV,
>I~Q[
d1c+Ii%
private void processErrorCode(int nErrorCode) X=m^+%iD
{ |3B<;/v5
System.err.println("Error Code : " + nErrorCode); 7~Inxk;
} W =Bw*o-
l\V1c90m
BRY/[QRqZ
//停止文件下载 -o"b$[sf=Z
public void siteStop() WUz69o be
{ 3>L5TYa
bStop = true; }MMKOr(
for(int i=0;i<nStartPos.length;i++) [efU)O&
fileSplitterFetch.splitterStop(); b?iPQ$NyQ
DDGDj)=`
U7n#TPet
} >Q@y8*E\F
} Os>&:{D4!
//负责部分文件的抓取 Myg;2.
**FileSplitterFetch.java g7hI9(8+
*/ m`8{arz2
package NetFox; J>T98y/))
JS m7-p|E
0H4|}+e
import java.io.*; qCrpc=
import java.net.*; lv!j
Y(1?uVYW\d
Tb2#y]27
public class FileSplitterFetch extends Thread { psIo[.$rTk
j96}E/gF
4V,p\$;
String sURL; //File URL }qp)VF
long nStartPos; //File Snippet Start Position 7Rtjm
long nEndPos; //File Snippet End Position V1d#7rP
int nThreadID; //Thread's ID ?b(wZ-/
boolean bDownOver = false; //Downing is over s Y1@~v
boolean bStop = false; //Stop identical s=jH1^
FileAccessI fileAccessI = null; //File Access interface ZaY|v-
w$iPFZC'
tF/Ni*\^rV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;g#nGs>
{ 7w9'xY
this.sURL = sURL; /2=9i84
this.nStartPos = nStart; `.~S/$a.&
this.nEndPos = nEnd; P(@Q[XQ2
nThreadID = id; '#=n>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U%@C<o "
} S` U,
3D@3jyo:
5p~5-_JX
public void run() d]|K%<+(
{ _>`9]6\&
while(nStartPos < nEndPos && !bStop) /]J\/Z>
{ zTMLE~w
T&6>Eb0{
yLCMu | +
try{ Dl0{pGK~
URL url = new URL(sURL); Z~94<*LEp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C"5P7F{
httpConnection.setRequestProperty("User-Agent","NetFox"); fHZ9wK>
String sProperty = "bytes="+nStartPos+"-"; i qxMTH#!
httpConnection.setRequestProperty("RANGE",sProperty); xa]yq%
Utility.log(sProperty); OYWHiXE6]
V73/q
PeiRe
InputStream input = httpConnection.getInputStream(); *mj=kJ7(
//logResponseHead(httpConnection); 6l4=
YGQ/zB^Pj
Io IhQ
byte[] b = new byte[1024]; G^h:#T
int nRead; "S'Yn-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +$>aT(q
{ ->;2CcpHB
nStartPos += fileAccessI.write(b,0,nRead); (AjgLNB
//if(nThreadID == 1) t%^&b'/Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,']CqhL6=R
} NA0Z~Ug>
Q{=r9&&
D{7^y>8_Y-
Utility.log("Thread " + nThreadID + " is over!"); <a_(qh@B
bDownOver = true; _(:$ :*@
//nPos = fileAccessI.write (b,0,nRead); &D-z|ZjgHi
} U&*%KPy`
catch(Exception e){e.printStackTrace ();} 9L-jlAo<
} VR"le&'z"
} \X(*JNQ
K@[Hej6d
}JQy&V%
//打印回应的头信息 b[:m[^
public void logResponseHead(HttpURLConnection con) 7p!f+\kM
{ C`qV+pV
for(int i=1;;i++) b=sY%(2s
{ r~QE}00@^
String header=con.getHeaderFieldKey(i); HWFTI /]
if(header!=null) *(vh|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '/loJz 1
Utility.log(header+" : "+con.getHeaderField(header)); 862rol
else ]i,o+xBKH
break; [P~7kNFOh
} |XQ_4{
} m-~3c]pA
,vMAX?c
Oop6o$k
public void splitterStop() wmR~e
{ %{V7|Azt
bStop = true; Fo;J3<U)
} Qof%j@
RSB+Saf.8
bxO/FrwTj{
} hCgk78O?
4=y&}3om(0
as/PM"
/* _~umE/tz
**FileAccess.java `h:!^"G
*//文件访问(定位，写) 2Rwd\e.z
package NetFox; `) ],FE*:
import java.io.*; sieC7raO
9qGba=}Ey
w9"~NK8xzM
public class FileAccessI implements Serializable{ y}={S,z%22
ZO<\rX (
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OA}; pQ9QN
RandomAccessFile oSavedFile; g__s( IJ
long nPos; dOaCdnd~
jbT{K|d-
6v%ePFul
public FileAccessI() throws IOException $7Z-Nn38
{ 6#jql
this("",0); %B1TN#KoT
} <0~1
[x=(:soEqC
sHPeAa22
public FileAccessI(String sName,long nPos) throws IOException d>MDC . j
{ 74 )G.!
oSavedFile = new RandomAccessFile(sName,"rw"); Tu}EAr
this.nPos = nPos; \=|=(kt)
oSavedFile.seek(nPos); vQ2{+5!|
} Rq?t=7fX)
H!"TS-s`
g;[t1~oF
public synchronized int write(byte[] b,int nStart,int nLen) ofz?L#:2
{ 1.8"N&s
int n = -1; %8Y+Df;ax
try{ CHO_3QIz
oSavedFile.write(b,nStart,nLen); >@?mP$;=
n = nLen; ~g#/q~UE
} suWO:]FR
catch(IOException e) fY78
{ HSU?4=Q
e.printStackTrace (); HFyQ$pbBU
} !OPHS^L
%yfl-c(u
b *0uxvLu
return n; !:esdJH
} L0=`1q
LLzxCMc9*
UpSJ%%.n
} Ijz*wq\s;
*M#L)c;6
-,g.39u
/* .YB/7-%M[
**SiteInfoBean.java c\ZnGI\|
*/ Ml?KnSb
package NetFox; S&[9Vb
'?_~{\9<
gzW{h0iRr
public class SiteInfoBean { 4eSFpy1
DaGny0|BB
&{qKoI]
private String sSiteURL; //Site's URL >RJ&b
private String sFilePath; //Saved File's Path eFA,xzp
private String sFileName; //Saved File's Name yQ<h>J>
private int nSplitter; //Count of Splited Downloading File B *6ncj
p_JWklg^
"j8=%J{
public SiteInfoBean() l1L8a I,8
{//nSplitter的缺省值为5 `e3$jy@
//default value of nSplitter is 5 JwWxM3(%t
this("","","",5); Y8lZ]IB
} SH8zkAA7u}
8s[1-l
-lv(@7o~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $XkO\6kh
{ /yY}.S
sSiteURL= sURL; +NvpYz
sFilePath = sPath; L=HnVgBs
sFileName = sName; x`IWo:j
this.nSplitter = nSpiltter; 7D'D7=Z.
q j9q
QSM3qke
} ! jDopE0L
9pS:#hg
yn<J>e
public String getSSiteURL() j]R[;8g
{ Q^05n$ tI
return sSiteURL; BYa#<jXtAT
} a+~b3
$o$WFV+h
w2('75$J
public void setSSiteURL(String value) UH\{:@GjNO
{ 4"!kCUB
sSiteURL = value; B J IN
} C"s-ttP
EymSrZw
w5/6+@}
public String getSFilePath() [>3dhj[;
{ b9-3
return sFilePath; Y}Y~?kE>M|
} lHTr7uF(
oZl%0Uy?9I
15aPoxo>
public void setSFilePath(String value) ?q2Yk/P
{ BTG_c_?]e
sFilePath = value; V+l7W
} y;<}`
'<1Cta`
ORWi+H|
public String getSFileName() ]A#:Uc5
{ MOp "kA
return sFileName; >NV1#\5_R@
} oEFo7X`t
)<_qTd0`
:^>&t^E
public void setSFileName(String value) u5KAwMw%Q
{ Iij$ce`nx
sFileName = value; O2="'w'kR
} :7dc;WdM
'}bmDb*
&o1k_!25
public int getNSplitter() 8xhx*A
{ A2A_F|f
return nSplitter; v.u 5%
} e+VE FWz
C>,> _
! R3P@,j
public void setNSplitter(int nCount) R?- zJ ;
{ qcQq.cS_'N
nSplitter = nCount; X{6a
} BB(v,W
} DVKb`KJ"
`R.Pz _oe
hk S:_e=
/* UTN[!0[
**Utility.java .P?n<n#
*/ 2Yd@V}
package NetFox; k"/Rjd(;
9e vQQN6D|
)N1iGJO)
public class Utility { v'^}zO
c813NHW
<X1lq9 lW
public Utility() _p'@.P
{ -"H0Qafm
w1VYU>
"5sA&^_#_
} T.-tV[2
zn_#}}e;G
//线程睡眠 9$C?)XKXB
public static void sleep(int nSecond) X')l04P@%
{ 8Djki]
try{ DQ[7p(
Thread.sleep(nSecond); d&f!\n_~
} 3?L[ohKH?:
catch(Exception e) -!li,&,A1
{ >+Iph2]
e.printStackTrace (); nLv~)IQ}:
} Fpeokr"i
} de.f?y
n4}e!
//日志 khD)x0'b
public static void log(String sMsg) g#7Q-n3^
{ }&2,!;"">3
System.err.println(sMsg); v9S=$Aj
} `8Ych@f]
uwZ,l-6T
<o*b6m%
public static void log(int sMsg) RO%M9LISI
{ PB5h5eX
System.err.println(sMsg); |JHNFs
} T{"Ur:p
} n~}[/ly
k)X\z@I'
$N;J)
/* d%epM5
**TestMethod.java cs9h\]ZA
*/ -/0\_zq7
package NetFox; Q4a7g$^
e#mqerpJ
2k^rZ^^"
public class TestMethod { V3r)u\ o'
MuP>#Vk
3]9Rmx
public TestMethod() ,9_O4O%
{ ///xx/weblogic60b2_win.exe wAX;)PLg
try{ dGkw%3[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !IO\g"y~|%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b09xf"D
SiteFileFetch fileFetch = new SiteFileFetch(bean); [{[m)Z^
fileFetch.start(); /`DKX }
} 1@h8.ym<"
catch(Exception e){e.printStackTrace ();} 2/uZ2N|S
K9p<PLy+
-zqpjxU:
} \0_jmX]p
;Oqf{em];
']+!i a
public static void main(String[] args) CmBgay
{ >P\eHR,{-
new TestMethod(); c_M[>#`
} jWi~Q o+
} gTOx|bx
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