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)); 'G-VhvMv
} LE1&atq
for(int i=0;i<nEndPos.length-1;i++) !G\1$"T$
{ gQ?>%t]
nEndPos = nStartPos[i+1]; .4_~ku
} nn#A-x}~;b
nEndPos[nEndPos.length-1] = nFileLength; He#+zE;
} Oq+C<}eg
} $23="Jcl
iY;)R|6
gP/]05$e
//启动子线程 ,Oxdqxu7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Aba6/
for(int i=0;i<nStartPos.length;i++) kdxs{b"t
{ ZR..>=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E8%O+x}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^4s#nf:}
nStartPos,nEndPos,i); Dm 'Q&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3D<P [.bS
fileSplitterFetch.start(); IH>+P]+3"3
} )x( *T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AqN(htGvx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %#7M~RB[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LgBs<2
nEndPos = " + nFileLength); ^gb2=gWZ<
// fileSplitterFetch[nPos.length-1].start(); r\Man'h$
<&H.pN1_
0Fbq/63
//等待子线程结束 vtL)
//int count = 0; >St
//是否结束while循环 dZnq 96<:|
boolean breakWhile = false; vKaX,)P;?
6GJ?rE E/
S;|%'Sn|j9
while(!bStop) T( ;BEyc?
{ M.|hnGXN
write_nPos(); #wC4$y<>
Utility.sleep(500); |W#^L`!G
breakWhile = true; xss D2*l
?5/Sa
!3HMGzt
for(int i=0;i<nStartPos.length;i++) F'SOl*v(s5
{ jq}5(*k
if(!fileSplitterFetch.bDownOver) A;2?!i#f
{ Nb B`6@r
breakWhile = false; ~hM4({/QN
break; J+z0,N[
} snj+-'4T
} \J1Jn~
if(breakWhile) @x{;a9y
break; hV=)T^Q
^-=,q.[7
B&.XGo)
//count++; t%8*$"~X
//if(count>4) Gc SX5c
// siteStop(); DoImWNLo
} _-^KqNyy
noL<pkks~R
r--"JO%2
System.err.println("文件下载结束！"); 1}V_:~7
} ZEApE+m
catch(Exception e){e.printStackTrace ();} >nTGvLOq
} iLS'47
:r#FI".qx
gy*N)iv%
//获得文件长度 %X#Wc:b
public long getFileSize() L4Kkbt<x
{ 501|Y6ptl
int nFileLength = -1; [QL)6Xr
try{ ]LP&v3
URL url = new URL(siteInfoBean.getSSiteURL()); vH7"tz&RIp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f+gyJ#R`
httpConnection.setRequestProperty("User-Agent","NetFox"); A u(Ngq
"CLd_H*)c
neOR/]
int responseCode=httpConnection.getResponseCode(); BH%eu 7`t
if(responseCode>=400) ]A!Gr(FHQ
{ nDaQ1
processErrorCode(responseCode); odj|"ZK
return -2; //-2 represent access is error 4Jo:^JV
} qY0GeE>N
6'?Y]K
P_i2yhpK
String sHeader; Y+WOU._46I
sFB; /*C
j;<;?IW
for(int i=1;;i++) a"hlPJlG
{ tQUp1i{j\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PVV\@
//Utility.log(in.readLine()); |QxDjL<&t4
sHeader=httpConnection.getHeaderFieldKey(i); \!s0VEE
if(sHeader!=null) \Fc"Q@.u
{ SRj|XCd
if(sHeader.equals("Content-Length")) %.<w8ag
{ w,JB`jS)/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V^.~m;ETu]
break; n_?<q{GW
} ly6?jVJ
} wCc:HfmjJ
else .qF@ }dO
break; WvNX%se]3
} [)9bR1wh
} v)J6}H}e
catch(IOException e){e.printStackTrace ();} 8ae]tX5$
catch(Exception e){e.printStackTrace ();} sx(yG9
-Z]?v3 9
g4%x7#vz0
Utility.log(nFileLength); TvMY\e
y]M/oH
'J]V"Z)
return nFileLength; &|Z:8]'P
} uVOOw&q_
6}{2W<
_vvnxG!x&
//保存下载信息（文件指针位置） .ay K+6I
private void write_nPos() }q27M
{ WihOGdUS6
try{ 3}n=od=
output = new DataOutputStream(new FileOutputStream(tmpFile)); w.J2pvyB
output.writeInt(nStartPos.length); JTl 37j
for(int i=0;i<nStartPos.length;i++) Qe]@`Vg
{ t'0r4&\
// output.writeLong(nPos); o&gcFOM22
output.writeLong(fileSplitterFetch.nStartPos); I+8m1*
output.writeLong(fileSplitterFetch.nEndPos); nN/v7^^
} #.a4}ya19
output.close(); HIi"zo=V
} f{WJM>$:
catch(IOException e){e.printStackTrace ();} 7f[nNng
catch(Exception e){e.printStackTrace ();} 6"eGd"
} "uqa~R{
1wqCoDgkp
k/!Vv#8
//读取保存的下载信息（文件指针位置） xg\M9&J
private void read_nPos() e+4p__TmZ
{ 8~\Fpz|Og
try{ m7^a4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `H^Nc\P#
int nCount = input.readInt(); :#I8Cf
nStartPos = new long[nCount]; m-> chOu~|
nEndPos = new long[nCount]; G:A~nv9
for(int i=0;i<nStartPos.length;i++) 9j$ OU@N 8
{ fx%'7/+
nStartPos = input.readLong(); c*MjBAq
nEndPos = input.readLong(); !);}zW!
} Pw hs`YGMF
input.close(); ^=E4~22q
} ?2_u/x
catch(IOException e){e.printStackTrace ();} -!(3fO:
catch(Exception e){e.printStackTrace ();} c{rX7+bN
} w*#TS8 \
/2Y Nu*v
f+%J=Am
private void processErrorCode(int nErrorCode) zZki9P
{ +*!oZKm.
System.err.println("Error Code : " + nErrorCode); <74q]C
} :[|`&_D9J
wC'KI8-
-md2Z0^ Kc
//停止文件下载 n*@^c$&P
public void siteStop() +lO Y IQ
{ Nd^9.6,JU
bStop = true; Qj[4gN?}=
for(int i=0;i<nStartPos.length;i++) I)_072^O
fileSplitterFetch.splitterStop(); /PQg>Pa85
!*?&V3!
Nz*qz"T
} =lr*zeHLC
} Rj+}L ~"
//负责部分文件的抓取 .y+>-[j?B
**FileSplitterFetch.java $-M1<?5
*/ zP rT0
package NetFox; [)Xu60?Q
:4]&R9J>o
{BY`Wu:w
import java.io.*; ~k|~Q\
import java.net.*; 5(u7b
(U/6~r'.L
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public class FileSplitterFetch extends Thread { 57v[b-SK
cS4e}\q,
XRJ<1w:
String sURL; //File URL j)'V_@
long nStartPos; //File Snippet Start Position q+WOnTS
long nEndPos; //File Snippet End Position [WY NA-O
int nThreadID; //Thread's ID E I)Pfx"0
boolean bDownOver = false; //Downing is over <*2.B~
boolean bStop = false; //Stop identical gigDrf}
FileAccessI fileAccessI = null; //File Access interface |cWW5\/
P,_GTs3/G
1nBE8 N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &tLg}7?iB
{ cV&(L]k>`
this.sURL = sURL; 9n|H%AC
this.nStartPos = nStart; j 7a;g7.
this.nEndPos = nEnd; u9N?B* &{
nThreadID = id; at6f(+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TnPdpynP
} a!Z,~ V8
Fm*n>^P@Y
o=w&&B
public void run() }P-9\*hlm
{ xg. d)n
while(nStartPos < nEndPos && !bStop) 2ZNTg@o
{ L a0H
HTf7r-
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try{ +%UXI$v
URL url = new URL(sURL); QIBv}hgcy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9.#\GI ;
httpConnection.setRequestProperty("User-Agent","NetFox"); W*`2lf
String sProperty = "bytes="+nStartPos+"-"; fVb&=%e
httpConnection.setRequestProperty("RANGE",sProperty); Yt0 l'B%[u
Utility.log(sProperty); <3Co/.VQd
L7q%u.nB1
xI}]q%V
InputStream input = httpConnection.getInputStream(); .~ZNlI {K
//logResponseHead(httpConnection); #E{OOcM
)q&uvfQ1(
QOy+T6en
byte[] b = new byte[1024]; S[X bb=n
int nRead; D-E30b]e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s-o0N{b?#'
{ jP@H$$-=wH
nStartPos += fileAccessI.write(b,0,nRead); ,t*#o&+
//if(nThreadID == 1) ;gK+AU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y;xVB" (
} 4SY]Q[
.QRQvtd.
5s;HF |2x
Utility.log("Thread " + nThreadID + " is over!"); 6yv*AmFh
bDownOver = true; J@p[v3W
//nPos = fileAccessI.write (b,0,nRead); xh_6@}D2J
} i7mT<w>?
catch(Exception e){e.printStackTrace ();} }`h)+Im=
} ;}=v|Dr&I.
} vZhN% DfY
$-jj%x\}
My,ki:V?g6
//打印回应的头信息 qyp"q{k0
public void logResponseHead(HttpURLConnection con) iW.8+?Xq&
{ F>96]71 2
for(int i=1;;i++) +>44'M^Z|(
{ 6_^u}me
String header=con.getHeaderFieldKey(i); x AkM_<
if(header!=null) |XLx6E2F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6EGh8H f
Utility.log(header+" : "+con.getHeaderField(header)); [@uL)*o_#
else j'X]bd'
break; kNd[M =%
} $X9-0-
} z )a8 ^]`
)0yY|E\
7t0\}e
public void splitterStop() CP]BSyim'
{ -KCm#!
bStop = true; q,PB;TT
} ) e;)9~
]lXTIej`dy
UyEyk$6SU
} Y\& 4`v'
vz#rbBY*;
P%ev8]2
/* IT'~.!o7/
**FileAccess.java N$6Rg1
*//文件访问(定位，写) *G.6\
package NetFox; k$i76r
import java.io.*; <6Y o%xt
%K\_gR}V
j_o6+Rk
public class FileAccessI implements Serializable{ ?Q]&d!UCs
1Ty{k^%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <DvpqlT
RandomAccessFile oSavedFile; B&0-~o3WP
long nPos; p6A"_b^
4["$}O5
)^|zuYzN
public FileAccessI() throws IOException TMhUo#`I|
{ .o]vjNrd/
this("",0); s~6?p% 2]
} H/|Mq#K
"c\ZUx_i6
Y 'Yoc
public FileAccessI(String sName,long nPos) throws IOException cZe,l1$
{ S_y!4;]ox
oSavedFile = new RandomAccessFile(sName,"rw"); &s_[~g<
this.nPos = nPos; x&8HBF'
oSavedFile.seek(nPos); 9} :n
} A%Pjg1(uX
HH&`f3
0vqXLFf
public synchronized int write(byte[] b,int nStart,int nLen) +w?RW^:Q=
{ 1,p7Sl^h
int n = -1; yxf|Njo0
try{ ?}D@{%O3T
oSavedFile.write(b,nStart,nLen); +`r;3kH ..
n = nLen; N32!*TsWs
} Sy6Y3 ~7
catch(IOException e) 63#Sf$p{v
{ l5b? 'L
e.printStackTrace (); *T$`5|
} HpiP"Sl
O3bo3Cm$
;sE;l7
return n; I0h/x5
} vj]-p=
f]tc$`vb
T$U,rOB"
} :EJ+#
V:4]]z L}
N?eWf +C
/* ycg5S rg
**SiteInfoBean.java g)u ~GA*=
*/ X-|Lg.s
package NetFox; `f,SY
FX`SaY>D
Cu3^de@h
public class SiteInfoBean { dE=4tqv-r
l~kxt2&
rK;F]ei
private String sSiteURL; //Site's URL ~5<-&Dyp7
private String sFilePath; //Saved File's Path ujGvrYj
private String sFileName; //Saved File's Name &x =}m
private int nSplitter; //Count of Splited Downloading File 4:GVZR|-
;i\m:8!;
8@^=k.5IK
public SiteInfoBean() $-H#M]Gq
{//nSplitter的缺省值为5 w~wpm7
//default value of nSplitter is 5 GLrHb3@"N
this("","","",5); 4loG$l+a1
} [1K\ _
u;R<
0Ah'G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,_?P[~1
{ 2{:bv~*I0F
sSiteURL= sURL; ~UA:_7#\M
sFilePath = sPath; c193Or'6Y
sFileName = sName; #/a>dK
this.nSplitter = nSpiltter; ejP273*ah
2x%Xx3!
[(Ss^?AJW
} (!`TO{!6P
?.Z4GWyXa
[9dW9[Z+!
public String getSSiteURL() 3m:[o`L
{ {}!`v%z
return sSiteURL; YTP6m9hA+
} vDl6TKXcu
8D7=]
0h^&`H:
public void setSSiteURL(String value) EF1aw2
{ r/E'#5 Q
sSiteURL = value; `(NMHXgG+
} }j9V0`Q
_ T ;+*
+72[*_ <
public String getSFilePath() P?D;BAP2
{ $KDH"J
return sFilePath; 67<Ym0+ =
} nHiE$Y
6bj.z
:ZrE/3_S
public void setSFilePath(String value) -;rr! cQ?
{ Xi vzhI4
sFilePath = value; ;.*n77Y
} Y v22,|:
rq=D[vX\N(
5`];[M9
public String getSFileName() ?}<4LK]
{ q=Cc2|Ve
return sFileName; mFoE2?Y
} }AdA? :7A
Z1u:OI@(
yn&+ >{
public void setSFileName(String value) 6%N.'wf
{ 9cV;W\ Tw
sFileName = value; i4"BN,NZ{
} ,D#ssxV
:mOHR&2xR%
9a4Xf%!F>z
public int getNSplitter() }\+7*|
{ yffg_^fR
return nSplitter; C9+`sFau@
} qo,uOi
yMz%s=rh
>;|~ z\8
public void setNSplitter(int nCount) >SS YYy
{ hRKAs ]^j
nSplitter = nCount; 8#?jYhT7
} + Xc s<+b
} fyb:eO}
%qN_<W&Ze
kl(id8r
/* Rn] `_[)*~
**Utility.java G.#`DaP
*/ tXZE@JyuC
package NetFox; h%2;B;p]
,_ zivUU
cu)ssT
public class Utility { 3}U {~l!K
/HlLfW
a!OS2Tz:
public Utility() A:{PPjs%LA
{ 5X8GR5P
>j&+mii
kX0hRX
} OC(S"&D
P~"e=NL5
//线程睡眠 OHEl.p]|
public static void sleep(int nSecond) nu'r`
{ ]Tv0+ Ao
try{ LYYz =gvZl
Thread.sleep(nSecond); r8]y1 Om<
} A"yiXc-N~\
catch(Exception e) xK7xAO
{ kPuY[~i%
e.printStackTrace (); m{dXN=
} G[;GP0\N
} gL)l)}#
c/K:`XP~
//日志 p,(gv])ie
public static void log(String sMsg) Jf#Ika&px
{ J(0E'o{ug
System.err.println(sMsg); [:vH_(|
} 5X4 #T&.
]$4DhB
[2WJ];FJ
public static void log(int sMsg) [i"6\p&
{ o7_*#5rD
System.err.println(sMsg); G)(vd0X1
} {c(@u6l28
} \3WF-!xe
:NHP,"
-[h2fqu1
/* nBN+.RB:(
**TestMethod.java #![9QUvcf
*/ ZmXO3,sf)
package NetFox; E~4d6~s
BXzn-S
-@I+IKz
public class TestMethod { [Yi;k,F:
nfj8z@!
$u ae8h
public TestMethod() /i[1$/*
{ ///xx/weblogic60b2_win.exe KxA^?,t[
try{ t)p. $
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3QD+&9{D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); goMv8d
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?"+g6II
fileFetch.start(); VB}4#-dG?
} Ifx EM
catch(Exception e){e.printStackTrace ();} 7o99@K,
VfV|fuW
z1AYXW6F
} @5=2+ M
T4c]VWtD
~;QzV?%
public static void main(String[] args) MsD@pa
{ *WQl#JAr
new TestMethod(); f"Z2,!Z;
} ;^"#3_7T]
} U+4W9zhwo
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