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)); T(u;<}e@[
} +JYb)rn$^
for(int i=0;i<nEndPos.length-1;i++) tRI<K
{ "y~*1kBu
nEndPos = nStartPos[i+1]; q`mxN!1[
} sDBSc:5+e
nEndPos[nEndPos.length-1] = nFileLength; ~8&->?{
} ! 7V>gWhR
} .'o=J`|
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//启动子线程 }&+,y<>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _*UI}JtlS
for(int i=0;i<nStartPos.length;i++) :q3w;B~
{ 3:Nc`tM_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !2Ompcr1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1\,k^Je7
nStartPos,nEndPos,i); Gjeb)Y6N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g"" 1\rc=
fileSplitterFetch.start(); (b~l.@xh
} \},H\kK+^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -3yK>\y=|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5ph CEKt;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rZwSo]gp
nEndPos = " + nFileLength); (z8ZCyq7r[
// fileSplitterFetch[nPos.length-1].start(); 6h5g!GQD
! (lF#MG}
41=H&G&
//等待子线程结束 %r.OV_04
//int count = 0; &I=o1F2B)
//是否结束while循环 i/*)1;xsk
boolean breakWhile = false; dH5*%
syLdm3d|
<gi~:%T
while(!bStop) :Ni#XZ{F-/
{ cQ<|Of
write_nPos(); D(Rr<-(
Utility.sleep(500); V+D5<nICr
breakWhile = true; >'Lkn2WI
UH0l8ixc
{,uSDIOj$
for(int i=0;i<nStartPos.length;i++) rb@[Edj
{ +a*Ic8*
if(!fileSplitterFetch.bDownOver) >Z*b0j
{ ZDaHR-%Y
breakWhile = false; =Pn"nkpML
break; ]e-QNI
} s%y<FXUj
} j~Fd8]@
if(breakWhile) [Y!HQ9^LEp
break; XM5)|D
h/A\QW8Sd
7L/LlO/
//count++; +dLUq2
//if(count>4) ShVR{gIs
// siteStop(); Wn6m$=
} ]r!|@AWrQ\
bBML +0a
E> pr})^w
System.err.println("文件下载结束！"); Z] r9lC
} +JG05h%'
catch(Exception e){e.printStackTrace ();} k@%5P-e}
} [mwqCW&
1P*GIt2L
4y}z+4
//获得文件长度 [<d~b*/
public long getFileSize() =e 1Q>~
{ N/WtQSl
int nFileLength = -1; }@6yROy.
try{ j<)$ [v6
URL url = new URL(siteInfoBean.getSSiteURL()); !nL94:8U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?uc]Wgw"s
httpConnection.setRequestProperty("User-Agent","NetFox"); NG3:=
>A]l|#Rz
Uu+ibVM$
int responseCode=httpConnection.getResponseCode(); a!6r&<s=E
if(responseCode>=400) SJ22
{ cM9>V2:P
processErrorCode(responseCode); %4rlB$x
return -2; //-2 represent access is error xe6V7Wi/Tt
} KXx;~HtO
gktlwiCZ
X ]&`"Z]
String sHeader; 82r{V:NCK)
!7~4`D c6U
2vB,{/GXP
for(int i=1;;i++) ^y ', l
{ d< XY"Y%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p cUccQ
//Utility.log(in.readLine()); /QL<>g
sHeader=httpConnection.getHeaderFieldKey(i); cahlYv'
if(sHeader!=null) 'bZw-t!M@
{ n::i$ZUdK
if(sHeader.equals("Content-Length")) =;n>#<
{ ^"4?Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jJYCGK$=
break; }Gb^%1%M
} ()8=U_BFz
} NE`;=26c
else tjV63`LD
break; v@2?X4n
} B^/Cx
} 0Z((cI\J
catch(IOException e){e.printStackTrace ();} . P44t
catch(Exception e){e.printStackTrace ();} [`h,Ti!m<
8 rE`
bg9_$laDi
Utility.log(nFileLength); dUn]aS
[Z'4YXS
bZK`]L[
return nFileLength; %NlmLWF.
} SmyJ@.L"
4 }_}3.
u-n$%yDS
//保存下载信息（文件指针位置） Z$Ps_Ik
private void write_nPos() $hk_v~zM
{ >>R)?24,<
try{ ;1,#rTs
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZFX}=?+
output.writeInt(nStartPos.length); :+^`VLIf
for(int i=0;i<nStartPos.length;i++) N8r+Q%ov
{ `.VkR5/
// output.writeLong(nPos); PMQ31f/zf
output.writeLong(fileSplitterFetch.nStartPos); c}=[r1M*
output.writeLong(fileSplitterFetch.nEndPos); &,XPMT
} |M<R{Tt}nf
output.close(); } -hH2
} \sVzBHy d
catch(IOException e){e.printStackTrace ();} EG=U](8T
catch(Exception e){e.printStackTrace ();} },5LrX`L
} R 'mlKe x
W^:g_
6xh-m
//读取保存的下载信息（文件指针位置） XxB%
private void read_nPos() |QH )A
{ z}VCiS0
try{ B%[#["Ol
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |SJ%Myy
int nCount = input.readInt(); ^CDh! )
nStartPos = new long[nCount]; RKs_k`N0
nEndPos = new long[nCount]; .$G^c
for(int i=0;i<nStartPos.length;i++) j\.pS^+
{ ^=cXL
nStartPos = input.readLong(); /xA`VyHO
nEndPos = input.readLong(); h*[sV
} W89J]#v)k
input.close(); .d)H2X
} wE <PXBl\b
catch(IOException e){e.printStackTrace ();} M@.?l=1X
catch(Exception e){e.printStackTrace ();} :e_yOT}}
} lQ.3_{"s
|>I4(''}
kP~ ;dJD
private void processErrorCode(int nErrorCode) 9fSX=PVRmQ
{ uTrGb:^
System.err.println("Error Code : " + nErrorCode); rPW9lG
} cz>`$Zz
c$hoqi |tD
y3V47J2o
//停止文件下载 t&bE/i_T
public void siteStop() .|kp`-F51
{ =6w(9O
bStop = true; R&R{I/;i*.
for(int i=0;i<nStartPos.length;i++) W9SEYkg
fileSplitterFetch.splitterStop(); C%Op[H3
DGAg#jh
37,)/8]lG
} `jFvG\aC
} a<D]Gz^h
//负责部分文件的抓取 [;INVUwG^
**FileSplitterFetch.java MES|iB
*/ I1Gk^wO
package NetFox; ;{>-K8=>$
U &W}c^#
Cd'SPaR
import java.io.*; >\!>CuU
import java.net.*; }xzbg
~hA;ji|I
oakm{I|k}
public class FileSplitterFetch extends Thread { +@oo8io
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0l%|2}a
String sURL; //File URL RE:$c!E!
long nStartPos; //File Snippet Start Position Riz!HtyR
long nEndPos; //File Snippet End Position &4l>_
int nThreadID; //Thread's ID 9=^4p=1J
boolean bDownOver = false; //Downing is over .l&<-l;UQ
boolean bStop = false; //Stop identical Ed~2Qr\65
FileAccessI fileAccessI = null; //File Access interface D8_-Dvp7H
[W,maTM"
+4p gPv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Vt,"5c
{ I:#Es.
this.sURL = sURL; O/Wc@Ln
this.nStartPos = nStart; (hX}O>
this.nEndPos = nEnd; & 5YI!; q,
nThreadID = id; al\ R(\p|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cvf#^Cu
} S)\%.~ n
ep"54o5=d
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public void run() 4q5bW+$Xj
{ ?l<u%o
while(nStartPos < nEndPos && !bStop) n\y%5J+
{ hG!"e4
((%g\&D
^t\AB)(8
try{ DPsf]
URL url = new URL(sURL); r5?qz<WW~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2L_ts=
httpConnection.setRequestProperty("User-Agent","NetFox"); bMw)>4
String sProperty = "bytes="+nStartPos+"-"; lTv_%hUp
httpConnection.setRequestProperty("RANGE",sProperty); DV/P/1E
Utility.log(sProperty); Z-+p+34ytq
Y;'7Ek)
wMB<^zZmv
InputStream input = httpConnection.getInputStream(); N^.!l_
//logResponseHead(httpConnection); rx#\Dc}
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q y8=4~40
byte[] b = new byte[1024]; Ge;plD-f
int nRead; U= PG0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >m{)shBX
{ HRKe 7#e
nStartPos += fileAccessI.write(b,0,nRead); 3E361?ubM
//if(nThreadID == 1) B/CP/Pfb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;2;Kq)j_=
} ' RjFWHAp
<4Jo1
8BZDaiE"
Utility.log("Thread " + nThreadID + " is over!"); S|%f<zAtJ
bDownOver = true; AcYL3
//nPos = fileAccessI.write (b,0,nRead); v(t?d
} MW+]w~7_Q
catch(Exception e){e.printStackTrace ();} b|*A%?m
} |3MqAvPJ
} rX#}2
5sq#bvfJ o
f13%[RA9N
//打印回应的头信息 d(L u|/~
public void logResponseHead(HttpURLConnection con) { LJRdV
{ YDyi6x,
for(int i=1;;i++) NY ZPh%x
{ 89'XOXl&1
String header=con.getHeaderFieldKey(i); )S|}de/a2
if(header!=null) bewi.$E{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1qb 3.
Utility.log(header+" : "+con.getHeaderField(header)); F3b[L^Km]
else bd2"k;H<o
break; `1KZ14K
} ;o#R(m@Lx
} eRa1eRgP
'7{0k{
!R WX1Z
public void splitterStop() '@iS5Fni
{ ~J6c1jG
bStop = true; dt 4_x1
} xF_ Y7rw1w
-)aBS3
:r[`bqC;\*
} fV_(P_C
?'h<yxu]u0
qf9.S)H1Z
/* #]|9aVrr
**FileAccess.java ge[+/$(1
*//文件访问(定位，写) ?zNv7Bj
package NetFox; (+9_nAgZ,
import java.io.*; HQ+:0"B
J+LFzl07q
uM0z%z5b
public class FileAccessI implements Serializable{ F[c;iM(^
%9=^#e+pE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Au"[2cG
RandomAccessFile oSavedFile; x1$tS#lS
long nPos; mD)_quz.sk
oZ@_o3VG
Y2w 9]:J
public FileAccessI() throws IOException M*E4:A9_M
{ r$6z{Na\[
this("",0); #oi4!%*M
} fdCsn:
.c+RFX@0
fdN-Zq@'
public FileAccessI(String sName,long nPos) throws IOException N@^?J@#V
{ Z| +/Wl-h
oSavedFile = new RandomAccessFile(sName,"rw"); Ne.W-,X^cL
this.nPos = nPos; }yU,_:
oSavedFile.seek(nPos); ^Yn{Vi2.
} e4ajT
h.g11xa
9QI\[lT&
public synchronized int write(byte[] b,int nStart,int nLen) ?jBna ~
{ ~-6Kl3Y
int n = -1; A[!Fg0X0
try{ oHbEHS61
oSavedFile.write(b,nStart,nLen); 'd1E~A
n = nLen; #Qy*zU#9
} >\$qF
catch(IOException e) QKbX^C
{ )D@1V=9,
e.printStackTrace (); BJk\p.BVN
} 6A/Nlk.
^C@uP9g
L$@^EENS
return n; 6$b"tdP
} p(~>u'c
+8Zt<snG
ho@f}4jhQ3
} ALwkX"AN
*n2Q_o
yIbz\3
/* M0x5s@
**SiteInfoBean.java o 1#XM/Z
*/ l0u6nGkh
package NetFox; +vLuzM-
'sY>(D*CQ
^,b*.6t
public class SiteInfoBean { T8ZBQ;o
FymA_Eq
OgS6#X
private String sSiteURL; //Site's URL qw0tw2|
private String sFilePath; //Saved File's Path z(>{"t<C
private String sFileName; //Saved File's Name EUe2<G
private int nSplitter; //Count of Splited Downloading File D_9&=aa'
=6j 5,
91%+Bf()J6
public SiteInfoBean() q[1H=+
{//nSplitter的缺省值为5 1U~AupHE
//default value of nSplitter is 5 -Z<e`iFQS
this("","","",5); bP Er+?fu
} ]<4Yor}t{;
/[GOs*{zB
f3V&i)w(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sxO_K^eD
{ rNqJL_!
sSiteURL= sURL; nV McHN
sFilePath = sPath; HQaKG4Z
sFileName = sName; [lQp4xgxi
this.nSplitter = nSpiltter; ,ye>D='
fmA&1u/xMs
HHCsWe-
} ^;NM'Z
1B6Go
+fAAkO*GP
public String getSSiteURL() . %tc7`k8
{ ).N}x^
return sSiteURL; TpZ) wC
} 8:L%-
NV*aHci
]BP/KCjAI<
public void setSSiteURL(String value) 3oxQ[.o
{ :{LVS nG
sSiteURL = value; &.=d,XKN
} U-3KuR+0
&EXql']
WaN0$66[:
public String getSFilePath() d<V+;">2
{ ^gH.5L0]gH
return sFilePath; phl5E:fIKx
} }^?dK3~q
68Wm=j.m
6H VS0
public void setSFilePath(String value) W8yr06{]
{ 2[9hl@=%
sFilePath = value; Trbgg
} =d7lrx+z
zBB4lC{q
"KW\:uc /
public String getSFileName() QCa$<~c
{ >efYpd#^
return sFileName; //Hn[wEOh
} -YA1Uk
\0(QO8.
mV`Z]-$$i
public void setSFileName(String value) # u^FB
{ *ta|,
sFileName = value; sTeL4g|%{
} cm-cwPAh
Si6%6rAhj
-Qiay/tlu
public int getNSplitter() kd|@.
{ xlgN}M
return nSplitter; &{x5 |$SD
} #?!)-Q%
n|SsV
$62ospR^Y
public void setNSplitter(int nCount) 26o68U8&y
{ k-Jj k3
nSplitter = nCount; <|hvH
} BA A)IQF
} }n:'@}
b,KQG|k
T9RR. ng
/* /ta-jOcRH&
**Utility.java Q++lgVh)E
*/ {G%`K,T
package NetFox; !(uyqplTk
)3'/g`c
8$OE<c?#5n
public class Utility { 2!7wGXm~U
yFl@z
/]F3t]FlC
public Utility() , YTuZS
{ `Kpn@Xg
Sw%=/g
SL pd~ZC?
} *;Hvx32I
7$Bq.Lc#z
//线程睡眠 ="d}:Jl
public static void sleep(int nSecond) `cy_@Z5A
{ +7^%fX;3pW
try{ =MB[v/M59w
Thread.sleep(nSecond); mAk)9`f/
} >e=tem~/
catch(Exception e) 6Nj\N oS
{ iKLN !QR
e.printStackTrace (); Wl;F]_|*(
} _+ oX9
} E2LpQNvN%g
<[8at6;
//日志 jGb+bN5U7
public static void log(String sMsg) qI^6}PB
{ 3"6lPUS
System.err.println(sMsg); X*]uLgbl
} +sQ=Uw#e
"sUL"i
w%S\)wjS
public static void log(int sMsg) [,8@oM#
{ >y(;k|-$
System.err.println(sMsg); zp!{u{
} &]ts*qCEL
} ]6GdB3?UVM
&Jk0SUk MP
8JJqEkQ
/* Fv.}w_
**TestMethod.java %gkRG66
*/ HP:ee+n
package NetFox; 1bYc^(z0
.,o=#
?E^~z-
public class TestMethod { ;R@zf1UYA
sn@gchO9s
r[q-O&2&
public TestMethod() QPg QM6
{ ///xx/weblogic60b2_win.exe yS@c2I602
try{ q$(aMO&J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k9~NIvnB`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8l~]}2LAs
SiteFileFetch fileFetch = new SiteFileFetch(bean); ltwX-
fileFetch.start(); aiF7\^aw$
} ^QpP'
catch(Exception e){e.printStackTrace ();} 2h IM!wQ
Uk`ym
i'H{cN6
} {SY@7G]
~ZweP$l
]EnB`g(4;
public static void main(String[] args) E<:XHjm
{ r.lH@}i%n
new TestMethod(); p3&/F=T;)
} D\}^<HW
} K9njD#/
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