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)); =M4:nt
} \P9ms?((A
for(int i=0;i<nEndPos.length-1;i++) jP_s(PQ
{ Ayg^<)JWh
nEndPos = nStartPos[i+1]; lF.kAEC
} lw}7kp4 2F
nEndPos[nEndPos.length-1] = nFileLength; ^'M^0'_"v
} C96*,.j~'
} pjTJZhT2I
r-!Qw1
0gW{6BtPWm
//启动子线程 _F`JFMS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R) dP=W*
for(int i=0;i<nStartPos.length;i++) Z|N$qm}
{ :aaX Y:<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %xG<hNw/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x3`JC&hF,q
nStartPos,nEndPos,i); @R%qP>_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lVq5>:'}^;
fileSplitterFetch.start(); LL (TD&
} `[#id@Z1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {~FPvmj&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "M-';;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NziCN*6
nEndPos = " + nFileLength); Ai[@2AyU
// fileSplitterFetch[nPos.length-1].start(); U_izKvEh
z#PaQp5F
w|S b`eR
//等待子线程结束 F<6(Hw#>
//int count = 0; {'h&[f>zcQ
//是否结束while循环 rb4;@&
boolean breakWhile = false; ;zo|. YD
oOvQAW8`
lOeX5%$Z
while(!bStop) $H)!h^7^9
{ &k_*Y-l7]
write_nPos(); [ei~Xkzkj
Utility.sleep(500); Keo<#Cc?
breakWhile = true; sU*?H`U3d
ovM;6o
*<67h*|)
for(int i=0;i<nStartPos.length;i++) C,eP!_O
{ FNF`Z
if(!fileSplitterFetch.bDownOver) DQxuV1
{ &ck}3\sQ
breakWhile = false; d|Wqx7t]P
break; =Hd#"9-
} sK+uwt
} _Y&.Nw
if(breakWhile) (2>q
break; F09%f"9
lGR0-Gh2
$"|r7n5[
//count++; cf"&22TQ+Z
//if(count>4) [Z:P{yr
// siteStop(); 3fQ`}OcNr
} 2/V%jS[4#y
|36%B7H
N1c0>{
System.err.println("文件下载结束！"); ~!5Qb{^
} \SQ4yc
catch(Exception e){e.printStackTrace ();} 2[pOGc$
} ]*k ~jY,
j?|Vx'
62'9lriQ
//获得文件长度 yBs-bp"-
public long getFileSize() obF|;fwPnR
{ {X?1}5ry
int nFileLength = -1; hLZfArq}
try{ KyVzf(^
URL url = new URL(siteInfoBean.getSSiteURL()); p\;8?x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WUz69o be
httpConnection.setRequestProperty("User-Agent","NetFox"); gvWgw7z
8g_kZ^<[
~<K,P
int responseCode=httpConnection.getResponseCode(); Pi?G:IF
if(responseCode>=400) T|BlFJ0"
{ [DeDU:
processErrorCode(responseCode); *`w>\},su
return -2; //-2 represent access is error VUUnB<j
} %SIll
aLm~.@Q
52o^]
String sHeader; $#5'c+0
b~tu;:
dg#Pb@7a
for(int i=1;;i++) hwe6@T.#
{ _MIheCvV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hV,T889'
//Utility.log(in.readLine()); FywX
sHeader=httpConnection.getHeaderFieldKey(i); v07A3oj
if(sHeader!=null) 4l*cX1!
{ p>?(uGV
if(sHeader.equals("Content-Length")) &P}t<;
{ 'Y ,2CN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zJ}abo6rVw
break; mpk+]n@
} (fl$$$
} 1QmOUw}yj
else 19O
break; @,,G]4zZ!
} [6g$;SicT
} 1CZO+MB&"$
catch(IOException e){e.printStackTrace ();} ,!^c`_Q\>@
catch(Exception e){e.printStackTrace ();} j]%XY+e
(r?hD*2r
nJv=kk1|o
Utility.log(nFileLength); l{^s4
^.@%n1I"5y
:!CnGKgt
return nFileLength; q!U$\Q&
} \5<Z[#{
G~&8/ s
2o[ceEg
//保存下载信息（文件指针位置） $i<+O,@-
private void write_nPos() {0,6-dd5
{ "v0bdaQH3
try{ H2[0@|<<
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5/U{b5
output.writeInt(nStartPos.length); St!0MdCH
for(int i=0;i<nStartPos.length;i++) ?ZC!E0]
{ q4!\^HwQ
// output.writeLong(nPos); [+A]E,pv]1
output.writeLong(fileSplitterFetch.nStartPos); $E;Tj|W
output.writeLong(fileSplitterFetch.nEndPos); r~QE}00@^
} nLk`W"irM
output.close(); jp4-w(
} rzie_)a Y%
catch(IOException e){e.printStackTrace ();} Hq>hnCT
catch(Exception e){e.printStackTrace ();} (#85<|z
} TT3GGHR
FY)]yz
?9eiT:2
//读取保存的下载信息（文件指针位置） ;C1#[U1Uy
private void read_nPos() lqrI*@>Tz
{ 2PeMt^
try{ SQ+r'g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =tA;JB
int nCount = input.readInt(); 6~{'\Z
nStartPos = new long[nCount]; :6(@P1vA 6
nEndPos = new long[nCount]; `) ],FE*:
for(int i=0;i<nStartPos.length;i++) (s|WmSQ
{ w3b?i89
nStartPos = input.readLong(); &ZFHWI(P
nEndPos = input.readLong(); O+<+yQl
} pih 0ME}z
input.close(); c}),yQ|!:
} ?+Vi !eS
catch(IOException e){e.printStackTrace ();} >hG*=4oh
catch(Exception e){e.printStackTrace ();} mv,a>Cvs[
} [%6)
6,~1^g*
aEa+?6;D
private void processErrorCode(int nErrorCode) /f oI.S
{ e~'z;%O~
System.err.println("Error Code : " + nErrorCode); hG<[F@d
} rhaq!s38:
'+iLW~
w<]-~`K
//停止文件下载 69:-c@L0
public void siteStop() !z2xm3s{]p
{ ([rSYKpi
bStop = true; EvY^]M_U
for(int i=0;i<nStartPos.length;i++) %FqQ+0^
fileSplitterFetch.splitterStop(); Vom,^`}
{^;7DV:
q;sZwp<
} C+`V?rp=s
} /$\8?<Pc".
//负责部分文件的抓取 {0/2Hw n
**FileSplitterFetch.java c\ZnGI\|
*/ }1Mf0S
package NetFox; /<+`4n
4eSFpy1
(=1zMZo
import java.io.*; (ToD u@p
import java.net.*; {=gJGP/}_
rL+.3ZO):P
gk5Gf l
public class FileSplitterFetch extends Thread { BjTgZ98J
J 48$l(l3
kou7_4oS
String sURL; //File URL X+,0;% p
long nStartPos; //File Snippet Start Position jpW_q+^?
long nEndPos; //File Snippet End Position JqYa~6 C
int nThreadID; //Thread's ID Nx*1m BC
boolean bDownOver = false; //Downing is over 7D'D7=Z.
boolean bStop = false; //Stop identical S^EAE]
FileAccessI fileAccessI = null; //File Access interface WMWMb3
,jw`9a
D8Mq '$-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nr}Ols
{ N@!PhP
this.sURL = sURL; P-8QXDdr
this.nStartPos = nStart; Vwjic2lGI
this.nEndPos = nEnd; gnxD'1_
nThreadID = id; oj'YDQ^uj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WT1y7+_g(d
} C"s-ttP
utC^wA5U~
15' fU!
public void run() B/n~ $
{ CW/L(RQ
while(nStartPos < nEndPos && !bStop) 15aPoxo>
{ !g=b=YK
Gui[/iY,F
0E (G1o'
try{ q0vZR"y
URL url = new URL(sURL); tw\1&*:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g:G5'pZf
httpConnection.setRequestProperty("User-Agent","NetFox"); &_hEM~{
String sProperty = "bytes="+nStartPos+"-"; _RZ"WA^[
httpConnection.setRequestProperty("RANGE",sProperty); "sY}@Q7
Utility.log(sProperty); IX<9_q
~.0'v [N
e5 zi"~
InputStream input = httpConnection.getInputStream(); e#3RT8u#
//logResponseHead(httpConnection); 6uUn
j*4:4B%
m@w469&<(q
byte[] b = new byte[1024]; FS!)KxC/-
int nRead; b^ [ z'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3=} P l,
{ v*<rNZI
nStartPos += fileAccessI.write(b,0,nRead); FCKyKn
//if(nThreadID == 1) 2Yd@V}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VhAJ1[k4!
} K~S*<?
8IBr#+0
Zkqq<
Utility.log("Thread " + nThreadID + " is over!"); (pd~ 2!;C
bDownOver = true; M}@>h
//nPos = fileAccessI.write (b,0,nRead); T.-tV[2
} 0) F\aJ4Y
catch(Exception e){e.printStackTrace ();} *">CEQ[MT
} Hr!$mf)h
} Wv;,@xTZ
-!li,&,A1
'RzO`-dr
//打印回应的头信息 ]+B.=mO_
public void logResponseHead(HttpURLConnection con) t imY0fx#
{ &rPAW V'v
for(int i=1;;i++) .c0u##/0
{ ,&o^}TFkg
String header=con.getHeaderFieldKey(i); :eJJL,v
if(header!=null) ,tg(aL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <hTHY E=
Utility.log(header+" : "+con.getHeaderField(header)); @EyB^T/
else tm2lxt
break; S $o1Q
} `YE=B{q
} :M f8q!Q'
zH9*w:"4<_
e5n]@mu%
public void splitterStop() 5;^1Ab0
{ V3r)u\ o'
bStop = true; ED" fi$
} Q.h.d))
6akI5\b
b09xf"D
} ',t*:GBZCf
|0}7/^
J:&.[
/* gH\>",[
**FileAccess.java tY!l}:E[
*//文件访问(定位，写) #=33TvprR2
package NetFox; o|c6=77043
import java.io.*; /~f[>#
Vwh;QJxb
e.%I#rNI
public class FileAccessI implements Serializable{ {#4a}:3
u~Po5W/i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Iz. h
RandomAccessFile oSavedFile; q9j~|GE|
long nPos; xU0iz{9
I2*(v%.-
Haekr*1%
public FileAccessI() throws IOException l5&5VC)
{ C/qKa[mg
this("",0); ytjZ7J['{
} /Wjc\n$'
]BjYUTNm
O2pE"8=4Q
public FileAccessI(String sName,long nPos) throws IOException izaqEz
{ I *sT*;U
oSavedFile = new RandomAccessFile(sName,"rw"); Us'JMZ~
this.nPos = nPos; ,pdzi9@=t
oSavedFile.seek(nPos); Zy;jp*Q
} N0kCdJv
FK~wr;[
d v[.u{#tP
public synchronized int write(byte[] b,int nStart,int nLen) ht]n*
{ $hcv}<$/
int n = -1; 7z1@XO<D
try{ DT>`.y%2W
oSavedFile.write(b,nStart,nLen); ,\P|%yv
n = nLen; stUv!
} 0|tyKP|J
catch(IOException e) YtSYe%
{ WKlqm)m@
e.printStackTrace (); S|k@D2k=
} <ml?DXT
Ua 6O~,\
t`|Rn9-
return n; &ZC{ _t
} ov,
UR_Ty59
p.g>+7
} mIYKzu_k=
$#s5y~z
[|eIax xR,
/* JcmMbd&B
**SiteInfoBean.java !J#P'x0
*/ x/M$_E<G
package NetFox; D3dh,&KO\
E2w-b^,5
<|Lz#iV37
public class SiteInfoBean { l{C]0^6>i
db_?da;!`
r`6f
private String sSiteURL; //Site's URL kjV>\e
private String sFilePath; //Saved File's Path r^C(|Vx
private String sFileName; //Saved File's Name uIO,9> ee
private int nSplitter; //Count of Splited Downloading File lrKT?siB
gvo98Id
x+6z9{O
public SiteInfoBean() iz/CC V L
{//nSplitter的缺省值为5 ?r&~(<^z
//default value of nSplitter is 5 ,JK0N_=
this("","","",5); FO_}9<s
} pn(i18x
}DjVZ48
jmv=rl>E*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gE@Pb
{ N5;z5E
sSiteURL= sURL; L{>rN`{
sFilePath = sPath; H9TeMY
sFileName = sName; j1{`}\e
this.nSplitter = nSpiltter; YiuV\al
iH-,l
Y)]VlV!`
} 5TuwXz1v
ATc!c +
jmq^98jB
public String getSSiteURL() vD9.X}l]
{ Y_y!$jd(N
return sSiteURL; UIf#Gy|l
} _7:Bxx4B
dPpQCxf
2&:z[d}~H
public void setSSiteURL(String value) ]=-=D9ZS3
{ 6%6dzZ
sSiteURL = value; 1:T"jsWw
} |*zgX]-+;
BWYv.&=(
)^qXjF
public String getSFilePath() _UkBOJ:G$H
{ gfAWN
return sFilePath; 5D7 L)>
} lj&\F|-i
r 56~s5A
9$X" D
public void setSFilePath(String value) AtHkz|sl
{ =eW4?9Uq
sFilePath = value; Px?"5g#+
} &I'J4gk[
-t<1A8%
8o,0='U
public String getSFileName() Oz(=%oS
{ CL5^>.}
return sFileName; ^5~x*=_
} GGHeC/4
o(54 A['
.HY,'oC.
public void setSFileName(String value) %K\B)HR
{ |p*cI @
sFileName = value; A9ld9R
} GK11fZpO:i
94 6r#`q
#H Jlm1d
public int getNSplitter() M"K$.m@t
{ fYZd:3VdC
return nSplitter; xp3^,x;\X
} .@;5"
@m`H~]AU
e9:pS WA-n
public void setNSplitter(int nCount) >^#Liwm
{ NhYUSk ~u
nSplitter = nCount; ~LFM,@
} "#8^":,4
} oLlfqV,|L\
_M;{}!Gc&A
o(v7&m;
/* ]-X\n
**Utility.java y[cc<wm$
*/ {4[dHfIy
package NetFox; <H<Aba9\
U~7{q >
&DtI+)[|
public class Utility { _m a;b<I/<
}7fzEo`g
'f %oL/,
public Utility() Q>w)b]d~c
{ v{1g`E
e2nZwPH
Bv*VNfUm
} +Ezl.O@z
Rdd9JJsVd
//线程睡眠 v=uQ8_0~N
public static void sleep(int nSecond) d|UH AX
{ Vj)"?|V
try{ 3_eg'EP.E
Thread.sleep(nSecond); \j we
} I;$tBgOWq
catch(Exception e) Skux&'N:
{ bgInIe
e.printStackTrace (); xw1,Wbu]
} McdK!V
} OWYY2&.h
yM-%x1r~
//日志 'P&r^V\~(/
public static void log(String sMsg) DuQ:82 3b
{ \IR$~
System.err.println(sMsg); zRau/1Y0
} dftX$TS
jM'Fb.>~
eo"XHP7ja
public static void log(int sMsg) 3VQmo\li
{ dsK^-e6:5
System.err.println(sMsg); Z\)P|#L$
} Au )%w
} oJ=u pnBn-
c8cGIAOY)
FQMA0"(G$
/* yW_goS0
**TestMethod.java P[Vf$ q<
*/ b0/[+OY
package NetFox; Z>'hNj)ju
xtXK3[s
t{ridA}
public class TestMethod { I?<ibLpX
_p+q)#.W
-]Oi/i,{
public TestMethod() ck`$ `
{ ///xx/weblogic60b2_win.exe yv5c0G.D
try{ @y# u!}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^DR`!.ttr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .noY[P8i
SiteFileFetch fileFetch = new SiteFileFetch(bean); ??P>HVx
fileFetch.start(); =Ajw(I[56
} w:9n/[
catch(Exception e){e.printStackTrace ();} X*:)]p(R
IBv9xP]BZ
m] IN-'
} b=Q%Jxz?
S3/Z]?o
55x.Q
public static void main(String[] args) XZPq4(,9}
{ \OF"hPq
new TestMethod(); wQ9fPOm
} 5CM]-qbf@
} *IC9))PGJ
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