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)); h>^jq{yu
} : 9?Cm`
for(int i=0;i<nEndPos.length-1;i++) ,Z*3,/a
{ So\|Ye
nEndPos = nStartPos[i+1]; -m'3L7:
} a,57`Ks+n<
nEndPos[nEndPos.length-1] = nFileLength; >,"D9!
} !!+/Wgd:6
} af?\kBm
KG-k$glD
^8-~@01.`_
//启动子线程 \,%o>M'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QVG0>,+}$
for(int i=0;i<nStartPos.length;i++) ;c m wh<
{ @maZlw1q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), itC *Z6^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %I|+_ z&x
nStartPos,nEndPos,i); hKH$AEHEU}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ss<_K>wk
fileSplitterFetch.start(); d1uG[
} (:y,CsR}4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }Uwkef.Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 27*(oT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zA'gb'MmW
nEndPos = " + nFileLength); -0KbdHIKb'
// fileSplitterFetch[nPos.length-1].start(); L=$?q/=-
-M1~iOb
c6Yf"~TD0
//等待子线程结束 S QM(8*:X
//int count = 0; WJY4>7}{B@
//是否结束while循环 R%)2(\
boolean breakWhile = false; RlslF9f
@!&Jgg53G
Y( V3PnH
while(!bStop) K[#v(<)
{ Qw6KX#n
write_nPos(); p-i.ITRS
Utility.sleep(500); uzVG q!'H
breakWhile = true; I_zk'
D*XZT{1g
g]==!!^<D
for(int i=0;i<nStartPos.length;i++) $||ns@F+
{ :?$Sb8OuIL
if(!fileSplitterFetch.bDownOver) ){:q;E]^fB
{ /H%<oAjp6
breakWhile = false; 3I;xU(rv
break; a*W_fxb
} ^z*):e
} 5!SoN}$
if(breakWhile) 0279g
break; 2Z/][?Jj{
ebO`A2V'(
rF8W(E_=
//count++; xqQ~|
//if(count>4) %0+h
// siteStop(); cXOje"5i
} -40'[a9E
}DDVGs[
r sX$fU8
System.err.println("文件下载结束！"); :_o] F
} _uO!N(k.
catch(Exception e){e.printStackTrace ();} Q{.{#G
} -'O Q-5
t?]\M&i&
55>" R{q
//获得文件长度 pBg|n=^
public long getFileSize() b"R, p=M
{ wO2V%v^bp
int nFileLength = -1; ,c,Xd
try{ l50|` 6t
URL url = new URL(siteInfoBean.getSSiteURL()); 08Pt(kzNA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -~vl+L
httpConnection.setRequestProperty("User-Agent","NetFox"); RjR&D?dc
C@TN5?Z
,>bGbx
int responseCode=httpConnection.getResponseCode(); [)Z'N/;0
if(responseCode>=400) cX|[WT0[I
{ .%x"t>]
processErrorCode(responseCode); p4m^ ~e
return -2; //-2 represent access is error p@?7^nIR*u
} e5qrQwU
L,Ao.?j
3bbp>7V!
String sHeader; &Q-[;
E3~,+68U
N_u&3CG
for(int i=1;;i++) "*Lj8C3|n
{ 8 3z'#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5u2{n rc
//Utility.log(in.readLine()); XKz;o^1a^
sHeader=httpConnection.getHeaderFieldKey(i); 1A7%0/K-]
if(sHeader!=null) lv<iJH\
{ .-SDo"K.h
if(sHeader.equals("Content-Length")) rao</jN.9
{ F[>7z3I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iGG6Myp-
break; xoqiRtlY:
} `3f_d}b
} 0K=Qf69Y
else CCbkxHMf|!
break; .dD9&n;#^
} B<|:K\MA
} .ocx(_3G
catch(IOException e){e.printStackTrace ();} XIr{U5$<6
catch(Exception e){e.printStackTrace ();} 2Pbe~[
xN#bzma
vOos*&
Utility.log(nFileLength); RL?u n}Qa
G{@C"H[$<
:7 qqjs
return nFileLength; AuoxZ?V
} DJmoW
A)\>#Dv
;;ER"N
//保存下载信息（文件指针位置） ybo#K
private void write_nPos() YniZ( ~^K
{ DRH'A!r!
try{ =?=)s
output = new DataOutputStream(new FileOutputStream(tmpFile)); gKmX^A5<
output.writeInt(nStartPos.length); GE%2/z p
for(int i=0;i<nStartPos.length;i++) u~" siH
{ ./5jx2V
// output.writeLong(nPos); :z B}z^8-
output.writeLong(fileSplitterFetch.nStartPos); Sa%zre@
output.writeLong(fileSplitterFetch.nEndPos); Gs+\D0o!
} ANckv|&'v
output.close(); VLf g[*k
} `@h:_d
catch(IOException e){e.printStackTrace ();} m_cO<LB
catch(Exception e){e.printStackTrace ();} DZ^=*.
} X Y~;)<s_
.qSBh hH\
7SBM^r}
//读取保存的下载信息（文件指针位置） ?QGmoQ)
private void read_nPos() D`~JbKV5@^
{ d!`lsh@tF
try{ ~_'0]P\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y.q>EUSH
int nCount = input.readInt(); _e6a8
nStartPos = new long[nCount]; >R(8/#|E
nEndPos = new long[nCount]; \M7I&~V
for(int i=0;i<nStartPos.length;i++) }ppVR$7]0
{ CV s8s
nStartPos = input.readLong(); *i`v~>
nEndPos = input.readLong(); h2"9"*S1
} -g:lOht
input.close(); 'nMApPl
} A^pu
catch(IOException e){e.printStackTrace ();} =g@R%NDNV
catch(Exception e){e.printStackTrace ();} zu52p4
} CE{z-_{^
Y5HfN[u^7
5d+<EF+N
private void processErrorCode(int nErrorCode) hF2/ y.:P
{ Yy]T J
System.err.println("Error Code : " + nErrorCode); L{=l#vu
} N;<//,
<D;MT96SG
vK(I3db!
//停止文件下载 J2r1=5HS
public void siteStop() Yrpxy.1=F5
{ cFLd)mt/
bStop = true; 4GVNw!V
for(int i=0;i<nStartPos.length;i++) $'^&\U~?
fileSplitterFetch.splitterStop(); YZibi
~uB'3`x
[Gh"ojt]w
} qh-[L
} ; yyO0Ha
//负责部分文件的抓取 tevQW
**FileSplitterFetch.java GJX4KA8J
*/ Y&s2C%jT
package NetFox; k5a\Sq}
e$/&M*0\f
h2% J/69
import java.io.*; ;+ G9-
import java.net.*; ^|aNG`|O
e&2wdH&
J/t!-!
public class FileSplitterFetch extends Thread { 4b4QbJ$
aM$\#Cx
eaQ90B4
String sURL; //File URL nX._EC
long nStartPos; //File Snippet Start Position 6yI}1g
long nEndPos; //File Snippet End Position hY+R'9
int nThreadID; //Thread's ID _9NVE|c;
boolean bDownOver = false; //Downing is over R uLvG+
boolean bStop = false; //Stop identical }kE87x'
FileAccessI fileAccessI = null; //File Access interface {rC~P
ZW*n /#GUC
\X& C4#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u?kD)5Nk
{ rs:Q%V ^
this.sURL = sURL; a=+T95ulDy
this.nStartPos = nStart; $M':&i5`,
this.nEndPos = nEnd; &8sV o@Pa
nThreadID = id; k(vPg,X>m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XrS\+y3
} )r9b:c\
W/r^ugDV
I]X
public void run() &!jq!u$(
{ #.<V^
while(nStartPos < nEndPos && !bStop) 6^;^rUlm
{ Pd~MiyO;K
2zK"*7b?
55-D\n<
try{ 9cQ_mgch
URL url = new URL(sURL); S5_t1wqBJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6e.v&f7(
httpConnection.setRequestProperty("User-Agent","NetFox"); [9V]On
String sProperty = "bytes="+nStartPos+"-"; BDe]18X
httpConnection.setRequestProperty("RANGE",sProperty); C c*({
Utility.log(sProperty); ]>Si0%
i[150g?K
W&(f&{A
InputStream input = httpConnection.getInputStream(); <C<`J{X0
//logResponseHead(httpConnection); iq6a|XGi
6z?gg3GV
~O: U|&
byte[] b = new byte[1024]; gi]ZG
int nRead; bU`=*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v7IzDz6gF
{ )`8pd 7<.
nStartPos += fileAccessI.write(b,0,nRead); t)N;'v &
//if(nThreadID == 1) j$x)pB3]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5)'P'kVi7.
} @T&t.|`
@Z;1 g
F Z!J
Utility.log("Thread " + nThreadID + " is over!"); ++8_fgM
bDownOver = true; lJ{V
//nPos = fileAccessI.write (b,0,nRead); 1$ML#5+,
} hazq#J!
catch(Exception e){e.printStackTrace ();} Pl+xH%U+?
} hVP IHQt
} 8$vK5Dnn8
`qiQ$kz
E=u/tpj
//打印回应的头信息 &Y7C0v
public void logResponseHead(HttpURLConnection con) (9$"#o
{ 0mexF@
for(int i=1;;i++) }rbZ&IN\?E
{ e*]r
String header=con.getHeaderFieldKey(i); jtKn3m7 +p
if(header!=null) :gI.l1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a3@w|KLt
Utility.log(header+" : "+con.getHeaderField(header)); !@g)10u
else 1f4bt6[
break; ;/LD)$_
} u+D[_yd^
} x*}bo))hb
4;KWG}~[o
0JY WrPR
public void splitterStop() [VSU"AJY
{ EO)%UrWnC
bStop = true; R$m`Z+/@
} 0a2@b"l
VC-;S7k
xx8U$,Ng
} rt4Z;
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$-vo}k%M
/* .L;@=Yg)
**FileAccess.java ,EEPh>cXc
*//文件访问(定位，写) $%2H6Eg0
package NetFox; bJ3(ckhq
import java.io.*; #cKqnk
j@1)K3Hga
Q:MhjkOr}
public class FileAccessI implements Serializable{ kzO&24
'Qn~H[$/p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SKXD^OH
RandomAccessFile oSavedFile; F}X0',
long nPos; 7m1KR#j
Q\kub_I{@
Sm|(
public FileAccessI() throws IOException m)&znLA
{ SEF6B45}1
this("",0); \#dl6:"
} =P^wh
+S~.c;EK
{G*QY%j^
public FileAccessI(String sName,long nPos) throws IOException GsV4ZZ
{ u oVNK
oSavedFile = new RandomAccessFile(sName,"rw"); 6Nh0
this.nPos = nPos; d^V$Z6* ]
oSavedFile.seek(nPos); E9 Y\X
} 9=+-QdX+0]
S>_27r{
;-@=
public synchronized int write(byte[] b,int nStart,int nLen) }zMf7<C
{ B|o%_:]+E
int n = -1; >a>fb|r
try{ {0yu
oSavedFile.write(b,nStart,nLen); Xm_$ dZ
n = nLen; BWUq%o,@g
} G'#41>q+
catch(IOException e) g9mG`f
{ l]#!+@
e.printStackTrace (); F^kwdS
} &%F@O<:
30F!kP*E
Y=B3q8l5
return n; fA^Em)cs2
} "="O >
\m/xV/
4$"DbaC
} uV]ULm#,i
*l>0t]5YH
i~yX tya
/* $3P`DJo
**SiteInfoBean.java eD;6okdP
*/ }e{qW
package NetFox; K|^wc$
TKI$hc3|L
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public class SiteInfoBean { 3y`F<&sA
f7<pEGb
.v`b[4M4
private String sSiteURL; //Site's URL e~\QE0Oe:
private String sFilePath; //Saved File's Path zlf}.
private String sFileName; //Saved File's Name Hi,t@!!
private int nSplitter; //Count of Splited Downloading File $H2GbZ-I
h)x_zZ%>o
RA/EpD:H
public SiteInfoBean() ps1@d[n
{//nSplitter的缺省值为5 FJS'G^
//default value of nSplitter is 5 pP/@
this("","","",5); &Cro2|KZhG
} zg}YGu|J
1'KishHK=
YUkud2,j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tz-X o
{ cCdX0@hY
sSiteURL= sURL; }NmNanW^
sFilePath = sPath; |X(2Zv^O
sFileName = sName; /Jlv"R1,
this.nSplitter = nSpiltter; ~1(j&&kXet
t/p $
1~5trsB+5
} G$JFuz)|
oRY!\ADR
IF_DZ
public String getSSiteURL() <+]f`c*Z
{ Je7RrCz
return sSiteURL; 3fkk [U
} FLr;`3
_N#&psQzw
vK$^y^
public void setSSiteURL(String value) #}yTDBt
{ 8 %Sb+w07
sSiteURL = value; Y& {|Sw7?
} ,E*R,'w
T{Zwm!s
v%91k
public String getSFilePath() B@K[3
{ {=JF=8@A
return sFilePath; -G`.y?
} Dz&+PES_k
jPJAWXB4a
v.g"{us
public void setSFilePath(String value) k*$3i
{ Z[L5 ;
sFilePath = value; H5xzD9K;/C
} i@$*Csj\9*
_"N\b%CkO
!`wW_W
public String getSFileName() Faac]5u:*
{ r/r:oXK
return sFileName; S%6U~@hig
} [_!O<z_sB
E`D%PEps+
4<v;1
public void setSFileName(String value) u<Xog$esu
{ H~fdbR
sFileName = value; .5Z_E O
} (xT*LF+
VXKT\9g3A
Re[:qLa]
public int getNSplitter() Q:o7G|C
{ ^%[F8\}XPJ
return nSplitter; NGTe4Crx
} ')TPF{\#
46XN3r
284zmZZ
public void setNSplitter(int nCount) 96ZdM=
{ ltA/
nSplitter = nCount; PZOKrW
} a(x?fa[D
} v3^|"}\q5
8Qrpa o
^Kq|ID AP
/* ^eh/HnJs
**Utility.java HnZPw&*
*/ ^ddO&!U
package NetFox; !: us!s
5K.+CO<
m_lrPY-
public class Utility { v'ay.oVzw
=>LZm+P
RU_L<Lpi
public Utility() ME+em1ZH
{ S+I^!gT
AV4~U:vU
*4yN3y
} 2$0)?ZC?=
}Ik1bkK
//线程睡眠 8LrK94
public static void sleep(int nSecond) i0Pn Z J
{ |B[eJq
try{ ($d4:Ww
Thread.sleep(nSecond); .W.;~`EW
} }~I|t!GL
catch(Exception e) |*\C{b
{ J!p<oW)a!
e.printStackTrace (); 0HibY[_PbD
} BQNp$]5s
} `,#!C`E 9
uHvaZMu
//日志 bZ5n,KQA5
public static void log(String sMsg) MCy~@)-IN
{ 4rp6 C/i
System.err.println(sMsg); ]VjLKFb~U
} U^$E'Q-VK
-2*>`,Uu
;z>p8N
public static void log(int sMsg) &]NZvqdj.]
{ 36A;!1
System.err.println(sMsg); EXbTCT}`x
} p\D >z("
} V SAafux
=vEkMJOs
3M N
/* 8hB.fau
**TestMethod.java 80&D""
*/ ?qT(3C9p
package NetFox; w}k B6o]
7),*3c')
GX38~pq
public class TestMethod { 08r[K(bfb,
K51fC4'{
RVF F6N^
public TestMethod() R^tcr)(
{ ///xx/weblogic60b2_win.exe /hci\-8N~
try{ ?5~!i9pY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s]x2DH+_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j|4tiv>
SiteFileFetch fileFetch = new SiteFileFetch(bean); |- OHve4A
fileFetch.start(); Xj,j0
} e_.~n<=
catch(Exception e){e.printStackTrace ();} (02g#A`
EfSMFPM
yN:>!SQ
} </ZHa:=7
9dYOH)f
3B#!2|
public static void main(String[] args) 0/Q5d,'Y[2
{ 'j#a%j@{
new TestMethod(); d*9j77C]
} [V5-%w^
} CWMlZVG
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