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)); {jggiMwo.v
} {IqbO>|"O_
for(int i=0;i<nEndPos.length-1;i++) UAUo)VVi"
{ )v0m7Lv#/
nEndPos = nStartPos[i+1]; A%%WPBk{O
} rw8db'
nEndPos[nEndPos.length-1] = nFileLength; oNl_r:G
} wzP>Cq
} SijCE~P
:mY(d6#A>
o)Ob}j
//启动子线程 `Z/"Dd;F^3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1mf|:2,
for(int i=0;i<nStartPos.length;i++) )CihqsA2
{ [A[vR7&S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nJA\P1@m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )jCAfdnCs
nStartPos,nEndPos,i); `6Y'H2WJ?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "m/0>UU0
fileSplitterFetch.start(); 9dSKlB5J
} +}X@{DB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 80axsU^H0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M0"xDvQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -zG/@.
nEndPos = " + nFileLength); {@B<$g
// fileSplitterFetch[nPos.length-1].start(); 3mr9}P9;
A!goR-J]
`')3}
//等待子线程结束 5I t+ S+a
//int count = 0; (Cqhk:F
//是否结束while循环 )[G5qTO
boolean breakWhile = false; $+:_>n^#/
.* VZY
.P-@ !Q5*
while(!bStop) *.W![%Be
{ sq&$
write_nPos(); 7lf* vqG
Utility.sleep(500); b~%(5r.
breakWhile = true; 8(5}Jo+
]?b#~
$6BXoh!
for(int i=0;i<nStartPos.length;i++) H-^>Co_
{ ks:Z=%o
if(!fileSplitterFetch.bDownOver) m_' 1yX@
{ AdR}{:ia
breakWhile = false; BEifUgCh
break; z/6eP`jj
} O6lj^
} V\X.AGc
if(breakWhile) vYrqZie<
break; d,+d8X
>g8Tl`P,iN
5A:b \
//count++; 1Cp5a2{
//if(count>4) n\wO[l)
// siteStop(); Pou`PNvH
} f{k2sU*uBE
iS=}| 8"
4CfPa6_
System.err.println("文件下载结束！"); }(20MW8rMc
} |V%Qp5 XJ
catch(Exception e){e.printStackTrace ();} $(.[b][S
} Y2QlK1.8V
[p[Kpunr{l
~48Uch\LG:
//获得文件长度 |f?tyQ
public long getFileSize() -~]*)&
{ J=|fxR
int nFileLength = -1; Da)9s %_4
try{ &37QUdp+p
URL url = new URL(siteInfoBean.getSSiteURL()); cZ%weQa#N)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *d?,i-Q.+
httpConnection.setRequestProperty("User-Agent","NetFox"); j01#Wq_\fk
|*i0h`a
GC~Tfrf=r
int responseCode=httpConnection.getResponseCode(); $Rd74;edn
if(responseCode>=400) *|a_(bQ4@
{ -:AknQq
processErrorCode(responseCode); a 0Hzf
return -2; //-2 represent access is error pRc@0^G
} $IUT5Gia`
yzgDdAM
kd9hz-*
String sHeader; d7N}-nsB
YeptYW@xfw
_;L9&>!p6
for(int i=1;;i++) i|)<#Ywl
{ 9ZeTS~i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~X*)gS-=
//Utility.log(in.readLine()); '8}*erAg
sHeader=httpConnection.getHeaderFieldKey(i); ja#E}`wC4
if(sHeader!=null) W;eHDQ|
{ 3?.3Z!H/
if(sHeader.equals("Content-Length")) ' DCrSa>
{ `N]!-=o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u-f_,],p
break; al(t-3`<
} E[)`+:G]
} Qf6Vj,~N
else -c~nmPEG6
break; {: T'2+OH>
} gH(,>}{^K
} @K3<K(
catch(IOException e){e.printStackTrace ();} HYZ94[Ti
catch(Exception e){e.printStackTrace ();} (/-2bO
/{."*jK
9~SfZ,(
Utility.log(nFileLength); A<ur20
wFnIM2a,
B|/=E470G
return nFileLength; cX9 !a,
} 4 B"tz!
p.SEW5
&S>m+m'
//保存下载信息（文件指针位置） V<ziJ7H/
private void write_nPos() am]$`7R5d
{ W}50E.\#
try{ Ze~^+ EE
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rjqeuyj:
output.writeInt(nStartPos.length); jn&[=Y-
for(int i=0;i<nStartPos.length;i++) '+hiCX-_
{ kid3@
// output.writeLong(nPos); Cdin"
output.writeLong(fileSplitterFetch.nStartPos); mg;+Th&
output.writeLong(fileSplitterFetch.nEndPos); C{`+h163\
} )[.FUx
output.close(); $8kc1Q
} )+'FTz` c
catch(IOException e){e.printStackTrace ();} d OQU#5
catch(Exception e){e.printStackTrace ();} U7bbJ>U_|
} m}54yo
/. k4Y
d3v5^5kU
//读取保存的下载信息（文件指针位置） \tc4DS
private void read_nPos() suC]
{ _VLc1svv
try{ )$p<BLU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MDZ,a0?4t
int nCount = input.readInt(); &^=6W3RD
nStartPos = new long[nCount]; E:a_f!
nEndPos = new long[nCount]; ,_,Z<X/
for(int i=0;i<nStartPos.length;i++) T>7$<ulm
{ $!h21
nStartPos = input.readLong(); <7NY.zvwk]
nEndPos = input.readLong(); ae`*0wbv
} :P1 J>dcG
input.close(); ]?whx&+
} 8=Xy19<;t
catch(IOException e){e.printStackTrace ();} s.d }*H-o
catch(Exception e){e.printStackTrace ();} OSY$qL2
} 'H+H4(
/>=)=CGv;
..`J-k
private void processErrorCode(int nErrorCode) hK5BOq!y
{ o?BcpWp
System.err.println("Error Code : " + nErrorCode); :s`~m;Y9?
} D[yOFJ~p)
j qfxQ
.Zv@iL5
//停止文件下载 %C^U?m`
public void siteStop() :Q@=;P2
{ ZCsL%(
bStop = true; fs_6`Xt
for(int i=0;i<nStartPos.length;i++) gVO<W.?
fileSplitterFetch.splitterStop(); 8h
L 1iA ^x
R>f$*T
} $9k7A 8K
} 1Tz5tU9kR
//负责部分文件的抓取 P(D0ru
**FileSplitterFetch.java DC4O@"
*/ _+73Y'
package NetFox; Y7g^ ?6
gmtp/?>e
Jn!-Wa,
import java.io.*; f86h"#4
import java.net.*; \Jq$!foYx
^x8*]Sz#x
}q7rR:g
public class FileSplitterFetch extends Thread { ;;#28nV
//T1e7)
fn(< <FA)
String sURL; //File URL GvQKFgO6h
long nStartPos; //File Snippet Start Position /Z`("X?_Kf
long nEndPos; //File Snippet End Position wq+%O,
int nThreadID; //Thread's ID gx,BF#8}
boolean bDownOver = false; //Downing is over mhU ?N
boolean bStop = false; //Stop identical #D4gNQg@R
FileAccessI fileAccessI = null; //File Access interface {8`V5:
D_mdX9-~
U-!+Cxjs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Zt;3HY=y
{ l-4+{6lz
this.sURL = sURL; fP<Tvf
this.nStartPos = nStart; iG*@(
this.nEndPos = nEnd; G>"=Af(t?Y
nThreadID = id; ?XOl>IO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0*G =~:
} 6?GR+;/
UolsF-U}'
u By[x 0
public void run() \[u7y. b
{ cXP*?N4Cf
while(nStartPos < nEndPos && !bStop) t6m&+N
{ {6}H}_(]
|Rk9W
9C9>V]
try{ 3Ov? kWFO
URL url = new URL(sURL); Ne>yFl"u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !Q(xA,p
httpConnection.setRequestProperty("User-Agent","NetFox"); CRXIVver
String sProperty = "bytes="+nStartPos+"-"; N<XS-XB,
httpConnection.setRequestProperty("RANGE",sProperty); )> >Tj7
Utility.log(sProperty); BCUn[4Gp
/~=W3lhY
[H"\<"1o
InputStream input = httpConnection.getInputStream(); LEu_RU?
//logResponseHead(httpConnection); k/'>,WE
dZ]['y%
e0rh~@E
byte[] b = new byte[1024]; Qy< ~{6V
int nRead; ICq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9*`(*>S
{ /XEt2,sI9
nStartPos += fileAccessI.write(b,0,nRead); p@`]9tLP(K
//if(nThreadID == 1) Zw4z`x1f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~\uI&S5
} R1A|g=kF
z''ITX)oG
m[l[yUw#
Utility.log("Thread " + nThreadID + " is over!"); 8nKZ
bDownOver = true; E+'P|~>oX
//nPos = fileAccessI.write (b,0,nRead); F`C$F!GE
} Y7q=]
catch(Exception e){e.printStackTrace ();} B}OM:0
} Xx)PyO
} b# v+_7
e$ pXnMx7
LHJ}I5zv
//打印回应的头信息 i"4&UJu1;
public void logResponseHead(HttpURLConnection con) CSu}_$wC#
{ Obj?,O
for(int i=1;;i++) =H8 LBM
{ mEh([ZnY
String header=con.getHeaderFieldKey(i); CGYZEPRR
if(header!=null) hzR1O(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2^3N[pM;
Utility.log(header+" : "+con.getHeaderField(header)); xJ=@xfr$
else 9|('*
break; mT:Z!sS
} "~:AsZ"7
} %t.L;G
DAvF ND$=
+c&oF,=}!P
public void splitterStop() ?^f=7e8]
{ gjbSB6[
bStop = true; vZ0K1UTEXY
} e"I+5r",
m@A?'gD
8l<4OgoK
} 4nvi7
%]U'
8Pgw_ 21N1
/* PjxZ3O
**FileAccess.java SO!|wag$
*//文件访问(定位，写) "bhF`,V
package NetFox; B_ x?s
import java.io.*; V DN@=/
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8k.<xWDU
public class FileAccessI implements Serializable{ I=;.o>
8gIf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &xgKHbg
RandomAccessFile oSavedFile; JA<Hm.V#
long nPos; 8*$HS.Db'
gL/D| =
_Qh:*j!
public FileAccessI() throws IOException *i`t4N A
{ iCZuE:I1K,
this("",0); PKxI09B
} YU]|N'mL2
zxD~W"R:s
KFuPgp
public FileAccessI(String sName,long nPos) throws IOException Dwx^hNh
{ dm:2:A8^
oSavedFile = new RandomAccessFile(sName,"rw"); dX^d\ wX
this.nPos = nPos; awC:{5R8v
oSavedFile.seek(nPos); 3<"!h1x5
} 1+Z@4;fk
9|{t%F=-
le*'GgU#
public synchronized int write(byte[] b,int nStart,int nLen) vB<2f*U
{ 8hZYZ /T
int n = -1; 7A=*3
try{ D\@)*"
oSavedFile.write(b,nStart,nLen); zn3]vU!
n = nLen; nD5+&M0
} ag*5fBF
catch(IOException e) Y<WA-dYoF
{ wRj||yay#-
e.printStackTrace (); EvJ<X,Bo
} 0e,U&B<W
t(.jJ>|+*
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return n; x o{y9VS
} V/dL-;W;
7.W$6U5
ahmxbv3f=5
} t`!@E#VK
&W*do
q L-Ni
/* tmgZNg
**SiteInfoBean.java &`LR{7m
*/ ;JHR~ TV
package NetFox; O,_k.EH
oa"_5kn,
\&,{N_G#L.
public class SiteInfoBean { 12TX_0
}b/Xui9Q
OTmw/#ug
private String sSiteURL; //Site's URL Co^^rd@
private String sFilePath; //Saved File's Path %Mxc"% w
private String sFileName; //Saved File's Name m2x=Qv][@c
private int nSplitter; //Count of Splited Downloading File p`=v$_]?(
9Z^\b)x
k )=Gyv<
public SiteInfoBean() d>1cKmH!
{//nSplitter的缺省值为5 IA3m.Vxj ^
//default value of nSplitter is 5 M/5+AsT
this("","","",5); }J0HEpn4
} tW[dJKw
MD+e!A#o
HbZFL*2x3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y8Oz4|
{ ]q":ta!f
sSiteURL= sURL; sD{d8s[(
sFilePath = sPath; ,w|Or}h]7
sFileName = sName; x4Wu`-4^
this.nSplitter = nSpiltter; wN2D{Jj
zS/1v+
A2p]BW&
} ?C`&*+
E06)&tF
UPGS/Xs]1
public String getSSiteURL() ('oA{,#L
{ 4DV@-
return sSiteURL; GWCU9n
} ?d5_{*]+v
pzFM#
gaC[%M
public void setSSiteURL(String value) .qfU^AHA
{ Zk<Y+!
sSiteURL = value; 8k9q@FSln
} k*e$_
]uZaj?%J<
Dk#4^`qp1
public String getSFilePath() +8Q5[lh2]j
{ "Gc\"'^r
return sFilePath; DPBWw[
} a2.@Zyz
m_C#fR /I
z`2Ais@ao
public void setSFilePath(String value) rGgP9 (
{ HvJ-P#
sFilePath = value; B{2WvPX~q
} |576)
,UATT]>
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public String getSFileName() J}Ji /
{ Rd|M)
return sFileName; G"|c_qX
} v&3 Oc
9FcH\2J
9w}_CCj3
public void setSFileName(String value) X(qs]:
{ ]\6*2E{1m
sFileName = value; N+CcWs!E
} z"$huE>P6
[n2)6B\/
= 6.i.(L_S
public int getNSplitter() WJBwo%J
{ dCO7"/IHW
return nSplitter; >7(7
} ['DYP-1J
x#jJ 0T
yGE)EBH
public void setNSplitter(int nCount) :S=!]la0h
{ Xp?WoC N
nSplitter = nCount; -oB`v'
} a(IZ2Zmr
} m.&"D> \t
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&]jCoBj+_
/* w|( ix;pK
**Utility.java miEf<<L#z
*/ (&oT6Ji
package NetFox; <hB~|a<#
G`R_kg9$
l*]nvd_
public class Utility { 3}x6IM2
RWdx)qj{
M <ccfU!
public Utility() >gZ"^iW
{ qLk7C0
F,h}HlU
4mwLlYZ
} }cd-BW
ROj9#:
//线程睡眠 #)z7&nD
public static void sleep(int nSecond) tr$d?
{ Bs';!,=
try{ .Dt.7G
Thread.sleep(nSecond); @X]JMicJ
} z18<rj
catch(Exception e) sV-UY!
{ !WNO!S0/j
e.printStackTrace (); |6T"T P
} tW=oAy
} t&nK5p95(
b0h>q$b
//日志 `V=F>s$W
public static void log(String sMsg) R:Tv'I1-L
{ R0bWI`$Z
System.err.println(sMsg); ^9`~-w
} }-%:!*bLj
~5 e 1&
q|S,^0cU
public static void log(int sMsg) f1X]zk(=W
{ U~_G *0
System.err.println(sMsg); ?Suv.!wfLl
} E#/vgm=W;
} (&xIBF_6
tN-B`d1
7-2,|(Xg
/* &U{"dJr
**TestMethod.java 'aJm4W&j
*/ wY_! s Qo
package NetFox; }080=E
v.{I^=
uV\~2#o$_
public class TestMethod { "= >8UR
EQ2HQz]
v0,&wdi
public TestMethod() e|Mw9DIW
{ ///xx/weblogic60b2_win.exe $X]Z-RCK3
try{ R*>EbOuI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yy4l -}"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0w ;#4X:m
SiteFileFetch fileFetch = new SiteFileFetch(bean); w02t9vz
fileFetch.start(); _0!<iN L
} [J+]1hCZ|
catch(Exception e){e.printStackTrace ();} "Tc[1{eI
M =6
E9#.!re|^
} MVZ9x%
K?X 6@u|h
U?(+ {4l
public static void main(String[] args) Rv@( [rn+
{ A=l1_8,`h
new TestMethod(); SS"Z>talw
} h f9yK6
} N3o kN8d
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