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)); 9,j-Vp!G
} [r+ZE7$2b"
for(int i=0;i<nEndPos.length-1;i++) hpTDxh'?$C
{ :cu#V
nEndPos = nStartPos[i+1]; qyC=(v
} 'r1LSht'
nEndPos[nEndPos.length-1] = nFileLength; !`1'2BC
} zDhB{3-Q1{
} <fCKUc
g~V+4+
qd3Q}Lk
//启动子线程 ~Tbj=f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4P^6oh0"
for(int i=0;i<nStartPos.length;i++) 7dsefNPb
{ 8 C[/dH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3(TsgP>`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vAY,E=&XvM
nStartPos,nEndPos,i); Y!iZW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z#BR5jF
fileSplitterFetch.start(); !Z VU,b>
} |@NiW\O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !EUan
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t!Sq A(-V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V%$/#sza
nEndPos = " + nFileLength); -*5Rnx|Y{
// fileSplitterFetch[nPos.length-1].start(); .920{G?l5
"-@[R
()&~@1U
//等待子线程结束 ^B8b%'\
//int count = 0; CLvX!O(~
//是否结束while循环 l Va &"
boolean breakWhile = false; r.7$&BCng
rZ8`sIWQt
ODZ|bN0>
while(!bStop) bfo["
{ lHgs;>U$
write_nPos(); Q.K,%(^;a
Utility.sleep(500); cGjPxG;
breakWhile = true; vfVj=DYj
8@so"d2e
y;/VB,4V
for(int i=0;i<nStartPos.length;i++) jKt7M>P
{ 2UGsYQn
if(!fileSplitterFetch.bDownOver) 4apL4E"r
{ D!7`CH+
breakWhile = false; x _c[B4Tw
break; (5]}5W*
} cnTaJ/o
} I? ,>DHUX
if(breakWhile) I`NjqyTW
break; #g6.Glz3
U&O: _>~
f^W;A"+
//count++; 9(QJT}qC
//if(count>4) j?'GZ d"B
// siteStop(); 98^V4maR:
} t!RiUZAo
5\z`-)
>2~=)L
System.err.println("文件下载结束！"); wI(M^8F_Mf
} k:7(D_
catch(Exception e){e.printStackTrace ();} ;!yQ
} (o`{uj{!
2}8v(%s p
5oAK8I
//获得文件长度 | Bi!
public long getFileSize() G^ :C+/)
{ l\i)$=d&g
int nFileLength = -1; ;^Dpl'v%\
try{ :OuA)f
URL url = new URL(siteInfoBean.getSSiteURL()); KCs[/]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R17?eucZ
httpConnection.setRequestProperty("User-Agent","NetFox"); h$2</J"
0Vx.nUQ
yqPdl1{Qr=
int responseCode=httpConnection.getResponseCode(); !r<pmr3f@7
if(responseCode>=400) ZHa"isl$e
{ <Y}R#o1Z
processErrorCode(responseCode); wb0L.'jyR)
return -2; //-2 represent access is error WlU0:(d
} VVlr*`
q<M2,YrbAI
jyCXJa-!-
String sHeader; a|X a3E
/'/Xvm3
&v@a5L
for(int i=1;;i++) LGn:c;
{ B6={&7U2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'dn]rV0(C
//Utility.log(in.readLine()); ez|)ph7
sHeader=httpConnection.getHeaderFieldKey(i); ]9^sa-8
if(sHeader!=null) ~sh`r{0
{ 1jcouD5?H
if(sHeader.equals("Content-Length")) }~L.qG
{ {tWf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^~etm
break; ')cMiX\v
} P5UL4uyl
} :.Wr{"`
else {z{bY\
break; yK=cZw%D
} A*\.NTM
} 5?x>9Ca
catch(IOException e){e.printStackTrace ();} :;9F>?VN>0
catch(Exception e){e.printStackTrace ();} r8RoE`/T
,>%}B3O:Y=
#pnI\
Utility.log(nFileLength); )P sY($ &
Bx< <~[Ws}
lNYt`xp
return nFileLength; JJN.ugT}1
} M<v%CawS
t7aefV&_,
ZpQ)IHA.
//保存下载信息（文件指针位置） cPlZXf
private void write_nPos() ]Gsv0Xk1
{ s*.hl.k.
try{ T{-CkHf9Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 50S&m+4d+
output.writeInt(nStartPos.length); _z|65H
for(int i=0;i<nStartPos.length;i++) C&(N I
{ Tw-;7Ae
// output.writeLong(nPos); ``hf=`We
output.writeLong(fileSplitterFetch.nStartPos); gtppv6<Mj4
output.writeLong(fileSplitterFetch.nEndPos); !2f[}.6+
} asppRL||
output.close(); R\!2l|_
} I=`U7Bis"
catch(IOException e){e.printStackTrace ();} Fj2BnM3#
catch(Exception e){e.printStackTrace ();} ,?^ p(w
} ,s"^kFl
N2;B-UF 7
\"P%`C
//读取保存的下载信息（文件指针位置） V2wb%;q
private void read_nPos() sBT2j~jhJ
{ s Z].8.
try{ r7%I n^k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9sYMSc~Bm
int nCount = input.readInt(); z7fp#>uw
nStartPos = new long[nCount]; Yi.N&&o
nEndPos = new long[nCount]; #Lh;CSS
for(int i=0;i<nStartPos.length;i++) *nkoPVpC
{ $Nhs1st*8
nStartPos = input.readLong(); inMA:x}cF1
nEndPos = input.readLong(); +~ P2C6@G
} !Wntd\w
input.close(); n{argI8wF
} m#| 9hMu
catch(IOException e){e.printStackTrace ();} Q+{xZ'o"Z
catch(Exception e){e.printStackTrace ();} AP?R"%
} &w_j/nW^'
tEvut=k'
*0Skd
private void processErrorCode(int nErrorCode) vApIHI?-
{ G[uK-U
System.err.println("Error Code : " + nErrorCode); 8;RUf~q?
} K0|FY=#2y
aC8} d
vXrx{5gz
//停止文件下载 YYBDRR"
public void siteStop() (c=6yV@
{ \ C+~m
bStop = true; 1#< '&Lr
for(int i=0;i<nStartPos.length;i++) dO! kk"qn
fileSplitterFetch.splitterStop(); T $>&[f$6
?]_$Dcmx
hj*pTuym
} %K=?@M9i
} <lPm1/8
//负责部分文件的抓取 \wz6~5R
**FileSplitterFetch.java l<58A7
*/ [}E='m}u9+
package NetFox; M^=zt
On9A U:\
@k,#L`3^
import java.io.*; FXG]LoP
import java.net.*; "c%0P"u
+>6iYUa
gwuI-d^
public class FileSplitterFetch extends Thread { o,\$ZxSlm
'CM|@Zz%
Tztu}t]N
String sURL; //File URL a/4T>eC
long nStartPos; //File Snippet Start Position Hw}Xbp[y
long nEndPos; //File Snippet End Position ?jv/TBZX4
int nThreadID; //Thread's ID @zW]2 c
boolean bDownOver = false; //Downing is over K7_UP&`=J
boolean bStop = false; //Stop identical +SR+gE\s0
FileAccessI fileAccessI = null; //File Access interface P^~yzI
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] vHF~|/-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException > PRFWO
{ ;#W2|'HD
this.sURL = sURL; p_gm3Q
this.nStartPos = nStart; u5`u>.!
this.nEndPos = nEnd; Q%`@0#"]Sv
nThreadID = id; 6jD=F ^jw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r= `Jn6@
} oGnSPI5KGC
we//|fA<
4#MtF'J
public void run() )0]'QLH
{ M6"PX *K
while(nStartPos < nEndPos && !bStop) SaO}e
{ -V77C^()8d
t%0VJB,Q2
tKOmoC
try{ {L{o]Ii?g
URL url = new URL(sURL); NZ:,ph
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y.(PiuG$G
httpConnection.setRequestProperty("User-Agent","NetFox"); %v M-mbX
String sProperty = "bytes="+nStartPos+"-"; x)DMPVB<
httpConnection.setRequestProperty("RANGE",sProperty); {BN#h[#B{
Utility.log(sProperty); G5BfNU
LYTdTP
Ko<:Z)PS
InputStream input = httpConnection.getInputStream(); U)o-8OEZ9
//logResponseHead(httpConnection); 2~)`N>@
`KoV_2|
z#wkiCRYm
byte[] b = new byte[1024]; T4Uev*A
int nRead; /l~p=PK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]m3HF&
{ lfow1WRF
nStartPos += fileAccessI.write(b,0,nRead); I5p? [
//if(nThreadID == 1) R`qFg/S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qz1E 2yJ
} PO:{t
UcHJR"M~c
Rsm^Z!sn
Utility.log("Thread " + nThreadID + " is over!"); yS'I[l
bDownOver = true; tCH!my_
//nPos = fileAccessI.write (b,0,nRead); 3qC}0CP*
} Gx/Oi)&/
catch(Exception e){e.printStackTrace ();} >y7?-*0
} 6@5+m 0`u3
} >1Ibc=}g
E<Y$>uKA
_ ]ipajT
//打印回应的头信息 L~OvY
public void logResponseHead(HttpURLConnection con) b{&)6M)zo
{ M'O <h
for(int i=1;;i++) ?dg[:1R}
{ %YscBG
String header=con.getHeaderFieldKey(i); Czu9o;xr
if(header!=null) 194)QeoFw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ax7[;|2
Utility.log(header+" : "+con.getHeaderField(header)); &K#M*B,*p
else IM'r8V
break; K;G~V\
} p8O2Z?\
} :P~6~ Kum
?);v`]
1.GQau~
public void splitterStop() O,f?YJ9S
{ <iC(`J$D
bStop = true; i-_mTY&M
} M5X&}cN6
%ntRG!
/$?}YL,
} Xl#ggub?
E{`fF8]K
G9cUD[GB
/* *]) `z8Ox
**FileAccess.java ]h+j)J}[A
*//文件访问(定位，写) qR8Lh( "i
package NetFox; FcU SE
import java.io.*; uw_Y\F-$
R&k<AZ
.Yn_*L+4*
public class FileAccessI implements Serializable{ eq;uO6[
}&J q}j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {4Cmu;u
RandomAccessFile oSavedFile; FvjPdN/L?R
long nPos; dR,fXQm
29.h91
@RKryY)
public FileAccessI() throws IOException zRr*7G
{ |)v,2
this("",0); ]{@-HTt
} ( Erc3Ac8
S2&4g/
+=</&Tm
public FileAccessI(String sName,long nPos) throws IOException ?0SJfh
{ hHnYtq
oSavedFile = new RandomAccessFile(sName,"rw"); }19\.z&J
this.nPos = nPos; \_f(M|
oSavedFile.seek(nPos); n{mfn*r.
} U'bEL^Jf
?Z/V~,
n/:33DAB
public synchronized int write(byte[] b,int nStart,int nLen) eD6fpe\(
{ @*((1(q
int n = -1; 1oGw4kD^x
try{ 8<Av@9 *}
oSavedFile.write(b,nStart,nLen); <0!):zraS
n = nLen; W/h[A3 `3N
} }K|oicpUg
catch(IOException e) |@d\S[~^G
{ NC(~l
e.printStackTrace (); &V/MmmT
} *z8\Lnv~k
k5pN
%*}(}~
return n; 2\{zmc}G-0
} uKHxe~
DB}eA N/
4H&+dRI"
} eng'X-x
+23xev
U>N1Od4vTO
/* L4nYXW0y
**SiteInfoBean.java wbl&
*/ ZD{LXJ{Vm
package NetFox; 6j}9V L77
4,DeHJjAlE
Y$@?.)tY
public class SiteInfoBean { /k3:']G,s
oCz/HQoBk
/7YIn3
private String sSiteURL; //Site's URL <RL]
private String sFilePath; //Saved File's Path <)D$51 &0
private String sFileName; //Saved File's Name 9\7en%(M
private int nSplitter; //Count of Splited Downloading File zTU0HR3A
Y76gJ[yjn
H4+i.*T#
public SiteInfoBean() ep{FpB
{//nSplitter的缺省值为5 ]h5tgi?_l
//default value of nSplitter is 5 eJ-nKkg~a
this("","","",5); C,4e"yynb
} fz "Y CHe
SvF<p3
=dN@Sa/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N;`n@9BF
{ 8Zd]wYO
sSiteURL= sURL; =T7.~W
sFilePath = sPath; tKXIk9e
sFileName = sName; *s3/!K
this.nSplitter = nSpiltter; u>vL/nI
X^jfuA
Xsa].
} 3!_XEN[
& 1f+,
dSHDWu&
public String getSSiteURL() G18b$z
{ TB31- ()
return sSiteURL; La[V$+Y
} 3ckclO\|>
`Urhy#LC
FGzwhgy
public void setSSiteURL(String value) 0w7DsPdS
{ ?}Y]|c^W
sSiteURL = value; q!@4~plz
} pd$[8Rmj_
_lq`a\7e
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public String getSFilePath() 6_B]MN!(
{ x kD6Iw
return sFilePath; MF'JeM;H
} 6ik$B
o)/ 0a
"#g}ve,
public void setSFilePath(String value) <1TAw.
{ <F'\lA9
sFilePath = value; J<lW<:!3]
} JW&gJASGC
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!5!<C,U
public String getSFileName() {{!-Gr
{ Q+{n-? :
return sFileName; Nz-&MS
} );YDtGip J
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public void setSFileName(String value) Q,Eo mt
{ k;Y5BB
sFileName = value; kq-) ^,{y
} (cO:`W6.
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3OB"#Ap8<
public int getNSplitter() noj0F::m`j
{ @2#lI
return nSplitter; yf,z$CR
} qxc[M8s
x?<FJ"8"k
mR)wX 6
public void setNSplitter(int nCount) vP,n(reM
{ N$tGQ@
nSplitter = nCount; *n!J=yS
} NxILRKwO
} `d(ThP;g
Iga024KR
\b>]8Un"
/* U$UIN#
**Utility.java ?q [T
*/ y1#1Ne_
package NetFox; L"aeG
\{D" !e
VxBo1\'
public class Utility { 2Khv>#l
=EsavN
\{YU wKK/A
public Utility() s#GLJl\E_P
{ qg$ <oL@~~
}-`4DHgq
nr#|b`J]
} rmOj
'c~4+o4co
//线程睡眠 W%Fv p;\`
public static void sleep(int nSecond) moE2G?R
{ eJX#@`K
try{ !'O@2{?B
Thread.sleep(nSecond); VtohL+
} 1E$|~
catch(Exception e) wgA_38To
{ Xwtqi@zlE
e.printStackTrace (); h yIV.W/
} [-x7_=E#
} k;W XB|k
Tsx>&WC
//日志 oL<St$1
public static void log(String sMsg) KY^Z
{ "wc<B4"
System.err.println(sMsg); 2Z%O7V~u
} D43z9z-:L
"Yy n/
t`QENXA}
public static void log(int sMsg) TsZ@
{ i@'dH3-kO
System.err.println(sMsg); =BrRYA
} K> e7pu
} >R=|Wo`Ri
FiU#T.`9'
3gf1ownC
/* |f##5fB
**TestMethod.java ?@8[e9lLD
*/ :v 4]D4\o
package NetFox; paMa+jhQQ
FgO)DQm
#LCb
public class TestMethod { LgYq.>Nl9
[00m/fT6
,+ ~W4<f
public TestMethod() I}Q2Vu<
{ ///xx/weblogic60b2_win.exe J=yTbSN\v
try{ =\d?'dII:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DTs;{c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }~q5w{_n
SiteFileFetch fileFetch = new SiteFileFetch(bean); ']oQ]Yx0
fileFetch.start(); [Nq*BrzF
} .|=\z9_7S8
catch(Exception e){e.printStackTrace ();} E} .^kc[(4
. ]M"# \
92-I~ !d
} {XHh8_^&
A)KZa"EX
|K~Nw&rZ]
public static void main(String[] args) ]%(2hY~i
{ y> (w\K9W
new TestMethod(); xLn%hxm?,
} H[|~/0?K
} ?1".;foZ
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