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)); EN` --^
} QL"fC;xUn,
for(int i=0;i<nEndPos.length-1;i++) 3X89mIDr
{ &Ph@uZ\
nEndPos = nStartPos[i+1]; B-|:l7
} YMj z,N
nEndPos[nEndPos.length-1] = nFileLength; ;:vbOG#aSN
} ^O6PZm5J}
} $d{{><
!h}x,=`z/
{tk42}8k
//启动子线程 3%|LMX]M5_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]Hc`<P
for(int i=0;i<nStartPos.length;i++) o?b$}Qrl
{ P-ys$=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -wvrc3F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NwIl~FNK
nStartPos,nEndPos,i); `]_#_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VT?JTW
fileSplitterFetch.start(); tmDI2Z%7
} NjMbQM4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }=?kf3k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5Lo{\7%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )/HSt%>
nEndPos = " + nFileLength); &`0y<0z
// fileSplitterFetch[nPos.length-1].start(); Z 3m5DK
L10Vq}W"
qi;@A-cq
//等待子线程结束 Pan^@B=Q
//int count = 0; he8y
//是否结束while循环 Ms=x~o'
boolean breakWhile = false; $L)9'X
]$KyZHj{
D\ HmY_
while(!bStop) 320Wm)u>:
{ DhG2!'N
write_nPos(); 36@)a5
Utility.sleep(500); `S2YBKz,1
breakWhile = true; m%m/#\J E
_=3H!b =
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for(int i=0;i<nStartPos.length;i++) vo-n9Bj
{ '=G4R{
if(!fileSplitterFetch.bDownOver) e57}.pF^
{ IfF<8~~E
breakWhile = false; 3:&!Q*i;
break; yP :>vFd7
} ~!E%GCyFy
} fa8vY
if(breakWhile) 4pJOJ!?
break; U O YM
lfOF]Kiqr
_FeLSk.
//count++; 4>uz'j<
//if(count>4) wz+
// siteStop(); R{NmWj['Mg
} 'C]zB'H=
[(BA:x1
Nj1vB;4Nx
System.err.println("文件下载结束！"); <8|vj2d2
} br.jj
catch(Exception e){e.printStackTrace ();} _:x/\8P
} f$Q#xlQM
sycN
u3R0_8 _.w
//获得文件长度 9IIQon
public long getFileSize() Vz1ro
{ @2v L'6
int nFileLength = -1; sOa`Tk
try{ J Xo_l
URL url = new URL(siteInfoBean.getSSiteURL()); $2A%y14
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rtS(iD@B"
httpConnection.setRequestProperty("User-Agent","NetFox"); DM/J,q
Qf6]qJa|
L)H7~.Dj
int responseCode=httpConnection.getResponseCode(); x|<rt966A
if(responseCode>=400) /(8Usu?g.
{ tQ< ou,
processErrorCode(responseCode); T)6p,l
return -2; //-2 represent access is error BEPeK
} ,@tYD(Z
\m1r(*Ar
A7>0Pn%D3
String sHeader; 3Ew-Ia%A
*>n<7T0
V.Dqbv
for(int i=1;;i++) g05:A0X#
{ ;JDn1(6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \9geDX9A
//Utility.log(in.readLine()); [?r`8K2!,
sHeader=httpConnection.getHeaderFieldKey(i); ?;i O
if(sHeader!=null) )TnxsFC
{ 0$b)@
if(sHeader.equals("Content-Length")) qXR>Z=K<
{ 5rRYv~+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Tm-Nz7U^^
break; h`-aO u
} C|5eV=f)P
} lsU|xOB
else MLtfi{;LH
break; |!euty ::
} 6AKH0t|4
} <%#M&9d)E
catch(IOException e){e.printStackTrace ();} F-k3'eyY
catch(Exception e){e.printStackTrace ();} P6&@fwJ<
51W\%aB
l3R`3@
Utility.log(nFileLength); ;g?oU"YM
dX-{75o5P
{1li3K&0s
return nFileLength; " |[w.`
} F<Js"z+
%Ui&SZ\
'e_^s+l)a
//保存下载信息（文件指针位置） L,*2tJcC<
private void write_nPos() tPIT+1.]z
{ xgn@1.}G
try{ OE]zC
output = new DataOutputStream(new FileOutputStream(tmpFile)); NVU@m+m~
output.writeInt(nStartPos.length); Iz*'
for(int i=0;i<nStartPos.length;i++) f9W@!]LHJ
{ jw?/@(AC6
// output.writeLong(nPos); ;:,hdFap
output.writeLong(fileSplitterFetch.nStartPos); k(+EY%
output.writeLong(fileSplitterFetch.nEndPos); Vcz ExP
} w{f!t8C*s
output.close(); v]& )+0
} XrS.[
catch(IOException e){e.printStackTrace ();} #56}RV1
catch(Exception e){e.printStackTrace ();} /.9j$iK#
} ;)s$Et%
wkOo8@J\
E;.<'t>
//读取保存的下载信息（文件指针位置） ~KHGh29
private void read_nPos() ,#hS#?t
{ OJPxV~y
try{ }-?_c#G3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t}>6"^}U
int nCount = input.readInt(); ~B;kFdcVXn
nStartPos = new long[nCount]; 3[B*l@}j
nEndPos = new long[nCount]; (Gr8JpV
for(int i=0;i<nStartPos.length;i++) O]>9\!0{
{ 4|YCBXWh
nStartPos = input.readLong(); fw$/@31AP?
nEndPos = input.readLong(); ;wwhW|A
} 8!2NZOZOS
input.close(); 8,=N~(pd`
} Pz7{dQqjk#
catch(IOException e){e.printStackTrace ();} pp@Jndlg
catch(Exception e){e.printStackTrace ();} 4*'5EBa1
} .lAqD-
T4dLuJl
k FE2Vv4.
private void processErrorCode(int nErrorCode) Cj"+` C)l
{ [[2Zcz:
System.err.println("Error Code : " + nErrorCode); n[8ju,=
} smvIU0:K
Tj7OV}:
teH.e!S
//停止文件下载 )w(-Xc?P
public void siteStop() 4Xt.}S!
{ GEj/Z};;[b
bStop = true; \ofWD{*j
for(int i=0;i<nStartPos.length;i++) by!1L1[JTt
fileSplitterFetch.splitterStop(); j oDY
Sm(X/P=z
)'3(=F$+l
} 1)yEx1
} 4XpW#>
//负责部分文件的抓取 :tU&d(8
**FileSplitterFetch.java -9TNU7^
*/ aNLRUdc.
package NetFox; H_RV#BW&
l/0"'o_0v#
11t+ a,fM
import java.io.*; .RFijr
import java.net.*; DuX7
{`?C5<r
*'4+kj7>
public class FileSplitterFetch extends Thread { 95LZG1]Rb
=?g26>dYo
r LQBaT7t#
String sURL; //File URL CeQL8yJ;
long nStartPos; //File Snippet Start Position {R<0'JU
long nEndPos; //File Snippet End Position q-gp;Fm
int nThreadID; //Thread's ID H8.Aq\2S
boolean bDownOver = false; //Downing is over ,l/~epx4v)
boolean bStop = false; //Stop identical hG51jVYtw
FileAccessI fileAccessI = null; //File Access interface Lc4\i
YHBH9E/B
j_H"m R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1AMxZ (e
{ 9RA~#S|(T
this.sURL = sURL; QJiU"1
this.nStartPos = nStart; Y3@\uM`2#
this.nEndPos = nEnd; \GhL{Awv&a
nThreadID = id; 0'8_:|5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y"zgpqJ
} u~SvR~OE
Hl-!rP.?0
&Ui*w%
public void run() IxN0m7
{ 7|Z=#3INw
while(nStartPos < nEndPos && !bStop) _+Tq&,_:o
{ ^ [FK<9
lh^-L+G:Ok
kS_oj
try{ Su.imM!
URL url = new URL(sURL); r:pS[f|4\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mbbgsy3W
httpConnection.setRequestProperty("User-Agent","NetFox"); `! ~~Wf'
String sProperty = "bytes="+nStartPos+"-"; ;#-yyU
httpConnection.setRequestProperty("RANGE",sProperty); dxHKXw
Utility.log(sProperty); %c+`8 wj
12l-NWXf
NqyKR&;
InputStream input = httpConnection.getInputStream(); [R V_{F:'
//logResponseHead(httpConnection); ,36AR|IO)
T%0vifoQ_$
o[Ojl.r<
byte[] b = new byte[1024]; K @x4>9 3n
int nRead; @o4+MQFn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n-ZOe]3
{ bu[PQsT
nStartPos += fileAccessI.write(b,0,nRead); Pnf|9?~$H
//if(nThreadID == 1) udw>{3>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); : L}Fm2^
} t~_j+k0K#
`zf,$67>1
+,oEcCi
Utility.log("Thread " + nThreadID + " is over!"); wxC&KrRF
bDownOver = true; (4:&tm/;
//nPos = fileAccessI.write (b,0,nRead); K>%}m,
} +5:Dy,F=
catch(Exception e){e.printStackTrace ();} ~V#MI@]V~
} a^:on?:9
} DJ&ni`
3JhT
f@JMDJ
//打印回应的头信息 UqVcN$^b
public void logResponseHead(HttpURLConnection con) GM]" $
{ q{4W@Um-
for(int i=1;;i++) BY*{j&^
{ $y%X#:eLJ
String header=con.getHeaderFieldKey(i); }5_[t9LX
if(header!=null) :mP%qG9U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }~B@Z\`O
Utility.log(header+" : "+con.getHeaderField(header)); h?t#ABsVK
else ~nQ=iB
break; K<k!sh
} 7kiZFHV
} Ih Yso7g
F+ ,eJ/]
~yX8p7qr
public void splitterStop() 1P8XVI'
{ *[VO03
bStop = true; QuB`}rfLf
} ~rnbuIh
T"h@-UcTl
.\Z/j
} kHWW\?O
2EO WbN}M
O_v8R7 {
/* +/"Ws'5E
**FileAccess.java IBP3
*//文件访问(定位，写) y4N8B:j%
package NetFox; cy_'QS$W
import java.io.*; j 3/ I=
hk5[ N=
RN,5>.w
public class FileAccessI implements Serializable{ 8>R 75dw
gKPqWh
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uUhqj.::<Y
RandomAccessFile oSavedFile; 6[.#B!;9
long nPos; f$7Xh~
#|92+
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public FileAccessI() throws IOException 2SjH7 '
{ p :v'"A}
this("",0); 4n9".UHh
} !O*'mX
`EBI$;!
%-nYK3
public FileAccessI(String sName,long nPos) throws IOException X jPPgI
{ J\@ r~x5G
oSavedFile = new RandomAccessFile(sName,"rw"); ,0hk)Vvr3
this.nPos = nPos; E=*82Y=B
oSavedFile.seek(nPos); xX !`0T7Y
} z_i(o
kv!QO^;^Y
w"PnN
public synchronized int write(byte[] b,int nStart,int nLen) f6of8BOg
{ b(E}W2-t
int n = -1; ^uWPbW&/q
try{ @p$Nw.{'
oSavedFile.write(b,nStart,nLen); l1M %
n = nLen; AfAlDM'
} mp'Z.4
catch(IOException e) Yg<L pjq5X
{ Ri
e.printStackTrace (); #oYPe:8|m
} 6D\$K
B5A/Iv)2
w$)NW57[|
return n; C{*' p+f
} {+3 `{34e
h]+UK14m
*jf%Wj)0M
} 21T#NYfew
MQ#nP_i
mhNX05D
/* ,J$XVvwxF
**SiteInfoBean.java n%S%a>IQj
*/ B,5kG{2!
package NetFox; ;_K3/:
&E?TR A# E
WR.>?IG2E
public class SiteInfoBean { XsEotW
mG*ER^Y@D
IDY2X+C#U
private String sSiteURL; //Site's URL !,cLc}a
private String sFilePath; //Saved File's Path QomihQnc
private String sFileName; //Saved File's Name : MEB] }
private int nSplitter; //Count of Splited Downloading File QM) ob
5(\H:g\z
|Wg!>g!
public SiteInfoBean() E]P7u"1
{//nSplitter的缺省值为5 2JhE`EVH
//default value of nSplitter is 5 X T<SR]
this("","","",5); "!B\c9q
} gTQc=,3l3
FKH_o
KY'x;\0 g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &v/>P1Z G
{ |muZv!,E
sSiteURL= sURL; vf@toYc[E
sFilePath = sPath; iAr]Ed"9|
sFileName = sName; yno X=#`
this.nSplitter = nSpiltter; 5-RA<d#
%HD0N&
W]oILL"d
} AX]cM)w
OQJ#>*?
6QYHPz
public String getSSiteURL() ujf]@L?
{ 8Q(A1U
return sSiteURL; so>jz@!EE
} ]@6L,+W"
8~}~d}wW
}rQ0*h
public void setSSiteURL(String value) JKF/z@Vbe\
{ "!9FJ Y
sSiteURL = value; !"LFeqI$lr
} 0O!A8FA0
|4j'KM;U
bIXD(5y
public String getSFilePath() RgD%pNhI
{ 3(,c^F
return sFilePath; bs_< UE
} %D49A-R
Y_FQB K U
4g)$(5jI}
public void setSFilePath(String value) !DkIM}.
{ }a"koL
sFilePath = value; -7IRlP&
} +&4@HHU{G
&U_T1-UR2
mM2DZ^"j(
public String getSFileName() EEP&Y?
{ Od+nBJ
return sFileName; ~hb;kc3
} 8 +mW
&e3pmHp'
T`2a)
public void setSFileName(String value) A\})H
{ 7?ILmYBw
sFileName = value; 0C4Os p
} AbL(F#{
}p>l,HD
L>n^Q:M
public int getNSplitter() %RIlu[J
{ Rxq4Diq5k
return nSplitter; gbu*6&j9
} q\/xx`L
fC+tu>=
+fN2%aC
public void setNSplitter(int nCount) ?!u9=??
{ G6bvV*TRi
nSplitter = nCount; .\+c{
} |*g\-2j{
} tN;^{O-(V
`0`#Uf_/$
iSNbbu#
/* 0E7h+]bh|
**Utility.java E <N%
*/ ]Na;b
package NetFox; Ch)E:Dvq6
: cPV08i
fS3%
public class Utility { >@EwfM4[e
+4F; m_G6
5`QfysR5
public Utility() y]g5S-G
{ `('NH]^
l%qfaU2
} x KvN
} em2Tet
JyePI:B&)j
//线程睡眠 L7"<a2J
public static void sleep(int nSecond) C'PHbo:
{ lNMJcl3
try{ 2RdpVNx\y
Thread.sleep(nSecond); tILnD1q
} Ym#io]
catch(Exception e) TA+#{q+a
{ "?6R"Vk?:
e.printStackTrace (); 3}B-n!|*
} OI:T#uk5
} 4{h^O@*g
|M EJ)LE7
//日志 @h\i<sh!^
public static void log(String sMsg) E)]emeGd
{ _8 l=65GW
System.err.println(sMsg); Q6n8,2*
} ~ujg250.L
[6?x 6_M
EcPvE=^c
public static void log(int sMsg) +&*>FeJY
{ a YY1*^
System.err.println(sMsg); u4xJ-Vu
} lUiO|
} `FK qVd
'i;ofJ[.c
o3`0x9{
/* 9y*(SDF
**TestMethod.java r<;Y4<,BZ
*/ F#o{/u?T
package NetFox; 5a/3nsup5
\5b<!Nl
f5R%F~
public class TestMethod { &<) _7?
wKJK!P
fN 1:'d
public TestMethod() 9Dyw4'W.N
{ ///xx/weblogic60b2_win.exe LNvkC4
try{ R(2MI}T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6wb M$|yFj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nTsPX Tat
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3]>YBbXvE
fileFetch.start(); }'\M}YM
} E8o9ufj3
catch(Exception e){e.printStackTrace ();} Y3xEFqMU
4-\4G"4
/sVmQqVY
} K,*IfHi6[
k,y#|bf,Y
mN#&NA
public static void main(String[] args) K4^B~0~
{ ?hW(5]p|
new TestMethod(); '=IuwCB|;
} G+iJS!=
} B,Jn.YX
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