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)); sP` k{xG
} $mF(6<w
for(int i=0;i<nEndPos.length-1;i++) F# a)"$j;
{ E~| XY9U36
nEndPos = nStartPos[i+1]; /`x)B(b
} sO;]l"{<
nEndPos[nEndPos.length-1] = nFileLength; }8\"oA6
} =JK# "'
} 8ba*:sb
(+=TKI<=
;xl_9Ht/
//启动子线程 noLb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !P"=57d}"l
for(int i=0;i<nStartPos.length;i++) zm9_[0
{ ` g5S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mm@)uV<\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zr1,A#BV
nStartPos,nEndPos,i); uV'w0`$y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Ky6|&!
fileSplitterFetch.start(); ==W`qC4n?n
} tG"lI/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 50Kv4a"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lDd8dT-Q.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1r-#QuV#
nEndPos = " + nFileLength); #]_S)_Z-
// fileSplitterFetch[nPos.length-1].start(); 1qgzb
(8?5REz
w]Fi:kV
//等待子线程结束 _;x7vRWmN
//int count = 0; FhyA_U%/nF
//是否结束while循环 5(}Qg9%
boolean breakWhile = false; A!\-e*+W=
GSh~j-C'
4-dV%DgC
while(!bStop) G._E9
{ oP0ZJK&;
write_nPos(); -?K?P=B;X
Utility.sleep(500); ?{bAyh/
breakWhile = true; *wY { ~zh
nOE 1bf^l
kpU-//lk+
for(int i=0;i<nStartPos.length;i++) ti}g?\VT
{ 5 Y|(i1
if(!fileSplitterFetch.bDownOver) Ksu_4dE
{ /t<C_lLM
breakWhile = false; 9}TQu0
break; a!?&8$^<
} }s7ibm'
} -Jj"JN.
if(breakWhile) ji~P?5(:
break; C*f3PB=H_
'r2VWavT
6IQkP9P(
//count++; JL7"}^
//if(count>4) dAZh# i[
// siteStop(); =IkG;gg
} e=<%{M&
>dTJ
w'-J24>=
System.err.println("文件下载结束！"); [Tq\K ^!^
} VIi/=mO]
catch(Exception e){e.printStackTrace ();} *Pmk1h2
} Q:+cLl&;hB
OlV'#D
V`7^v:
//获得文件长度 !_|rVg.
public long getFileSize() k\J 6WT
{ 9j6
int nFileLength = -1; >10pk
try{ .vbUv3NI
URL url = new URL(siteInfoBean.getSSiteURL()); p7YfOUo k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 51\N+
httpConnection.setRequestProperty("User-Agent","NetFox"); ]("5O V5
wv~?<DF
yye(^
int responseCode=httpConnection.getResponseCode(); W,[b:[~v
if(responseCode>=400) B9-Nb 4
{ )^ky @V
processErrorCode(responseCode); Js7D>GWP!
return -2; //-2 represent access is error ).Ei:/*j
} .LX8ko
yM8<)6=
J3$Ce%<
String sHeader; KP[H&4eoC
#Ang8O@y
#O |Z\|n
for(int i=1;;i++) mOUIGlv
{ GG}(*pOr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J7C2:zj
//Utility.log(in.readLine()); SuHv{u45
sHeader=httpConnection.getHeaderFieldKey(i); mN9Uyz5G
if(sHeader!=null) 7JedS
{ ;{Sgv^A
if(sHeader.equals("Content-Length")) e0#/3$\aSV
{ 2[*r9%W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R&OqmhT!
break; (;11xu
} =>0+BD
} #]@<YKoV{
else <Rl:=(]i~
break; V`n;W6Q17
} -UPlQL
} 3]X9 z
catch(IOException e){e.printStackTrace ();} Jhyb{i8RR
catch(Exception e){e.printStackTrace ();} G|p3NhLgO=
~4Gs\U:!Q
MWHGB")J
Utility.log(nFileLength); nA\9UD<G.
4l2xhx
es` A<
return nFileLength; n tfwR#j
} Vo\RtM/6{
XQ{G)
UI*^$7z1 +
//保存下载信息（文件指针位置） 1Ugyjjlz
private void write_nPos() ?`nF"u>
{ YGA("<
try{ qXGAlCq@
output = new DataOutputStream(new FileOutputStream(tmpFile)); ::xH C4tw
output.writeInt(nStartPos.length); D{](5?$`|
for(int i=0;i<nStartPos.length;i++) >tq,F"2amC
{ @R|Gz/
// output.writeLong(nPos); CTbz?Kn
output.writeLong(fileSplitterFetch.nStartPos); %("Bq"Q8
output.writeLong(fileSplitterFetch.nEndPos); NjCdkT&g
} cdDMV%V
output.close(); #>|l"1
} ;9{x""
catch(IOException e){e.printStackTrace ();} Kzs]+Cl
catch(Exception e){e.printStackTrace ();} x=>+.'K
} ">n38:?R
[U]ouh)
nC3U%*l
//读取保存的下载信息（文件指针位置） uh~/ybR
private void read_nPos() P~)ndaQ
{ <&?gpRK
try{ Y}bJN%M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `>1"v9eF
int nCount = input.readInt(); idC4yH42
nStartPos = new long[nCount]; 2 NgEzY5
nEndPos = new long[nCount]; LWB"}#vt
for(int i=0;i<nStartPos.length;i++) G36}4
{ U#O6l-xe]
nStartPos = input.readLong(); <(]e/}
nEndPos = input.readLong(); *ay>MlcV2=
} ?,JN?
input.close(); b[^=GF>e
} 8QeM6;^/5
catch(IOException e){e.printStackTrace ();} S^GB\uJ
catch(Exception e){e.printStackTrace ();} >A$J5B>d
} Fr}e-a
Y2 &N#~l*
T4dYC'z
private void processErrorCode(int nErrorCode) qIwI]ub~
{ 3 <V{.T
System.err.println("Error Code : " + nErrorCode); # $:ddOY
} |\ 1?CYx
9E (VU.
8 oHyNo
//停止文件下载 \(a9rZ9
public void siteStop() fq){?hk~O
{ OXC7 m
bStop = true; G\\zk
for(int i=0;i<nStartPos.length;i++) }mjJglK!N
fileSplitterFetch.splitterStop(); OE!:`Bo3T
GfAt-huL(
T,72I
} ~-,P1u!
} +e0]Y8J{
//负责部分文件的抓取 !*:Zcg?7n
**FileSplitterFetch.java u"K-mr#$[o
*/ ~RVx~hh
package NetFox; J?XEF@?'G
Ve,_;<F]S
1NO<K`
import java.io.*; ExDH@Lb
import java.net.*; Jy'ge4]3
H!Y`?Rc
*'+OA6
public class FileSplitterFetch extends Thread { %d+:0.+`n
IBx?MU#.
+igFIoHTM
String sURL; //File URL td@F%*
long nStartPos; //File Snippet Start Position R>"E Xq
long nEndPos; //File Snippet End Position " }@QL`
int nThreadID; //Thread's ID z.g'8#@
boolean bDownOver = false; //Downing is over :\Z;FA@g(g
boolean bStop = false; //Stop identical .`!|^h%0
FileAccessI fileAccessI = null; //File Access interface C#X0Cn0ln
A2z%zMlZc
B.&ly/d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NIDK:qdR
{ +[9~ta|j
this.sURL = sURL; 9n!<M)E
this.nStartPos = nStart; 4uv'l3
this.nEndPos = nEnd; ZpPm>|w
nThreadID = id; LSQ2pB2V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <lM]c
} %-+lud
/vFw5KUu
_9E7;ew
public void run() o/9(+AA>
{ da3]#%i0
while(nStartPos < nEndPos && !bStop) $4`RJ{ZJw]
{ _pQ9q&i4
guv)[:cd;
,MwwA@,9-
try{ rMqWXGl`(
URL url = new URL(sURL); " *xQN "F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /sENoQR
httpConnection.setRequestProperty("User-Agent","NetFox"); I<*U^e
String sProperty = "bytes="+nStartPos+"-"; dL>0"UN}-
httpConnection.setRequestProperty("RANGE",sProperty); b0]y$*{j
Utility.log(sProperty); H~+D2A
!`vm7FN"u
__""!Yz
InputStream input = httpConnection.getInputStream(); 3ug{1M3
//logResponseHead(httpConnection); TuphCu+Oh
4YkH;!M>ji
{4&G\2<^^
byte[] b = new byte[1024]; @B$ Y`eK\
int nRead; E7+y W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8vB~1tl;
{ Wx"bW ICc
nStartPos += fileAccessI.write(b,0,nRead); b/oJ[Vf
//if(nThreadID == 1) p"/1Kwqx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &C3J6uCm+
} /reSU 2
i\G@kJNnF
6q?C"\_
Utility.log("Thread " + nThreadID + " is over!"); 7Xv.C&jzd
bDownOver = true; %;9f$:U
//nPos = fileAccessI.write (b,0,nRead); !z X`M1J
} /ocdAW`0
catch(Exception e){e.printStackTrace ();} +Ij>\;vM"
} NA[yT
} bF:vD&Sf
;}3wT,=sN
cS,(HLO91
//打印回应的头信息 m2%uGqz
public void logResponseHead(HttpURLConnection con) $lci{D32,
{ 7ZS5u+o
for(int i=1;;i++) M)6_Tal
{ ,T_HE3K
String header=con.getHeaderFieldKey(i); =35^k-VS
if(header!=null) VB*$lxX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |UM':Ec
Utility.log(header+" : "+con.getHeaderField(header)); 3*64)Ol7t]
else 0R<@*
break; G@h6>O
} ]i\D*,FfU
} t/HMJ
Uf{cUY,j_
QvK/31*QG
public void splitterStop() V{;Mh u`+
{ |~k=:sSz{
bStop = true; [zIX&fPk$
} V;ZyAp
~my\{q
!Pt|Hk dr
} #ldNWwvRGj
^-PlTmT
(w?@qs!
/* =w0Rq~
**FileAccess.java _;$VH4(BI
*//文件访问(定位，写) 'Wl))lB
package NetFox; &fq-U5zH
import java.io.*; S1wt>}w0$
Nqp%Z7G
l%.3hId-
public class FileAccessI implements Serializable{ +wwpaR`
J`;G9'n2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,ju1:`
RandomAccessFile oSavedFile; 8$-Wz:X&
long nPos; MOP %vS
e2UbeP
Ps7(4%
public FileAccessI() throws IOException +w:[By"
{ Z<K[
this("",0); &G5+bUF,
} YMad]_XOP
)!hDF9O
d4/snvq
public FileAccessI(String sName,long nPos) throws IOException yC4JYF]JN
{ 3>yb$ZU"-
oSavedFile = new RandomAccessFile(sName,"rw"); fyT:I6*
this.nPos = nPos; *-T3'beg
oSavedFile.seek(nPos); uu1-` !%
} ~UB@IV6O
Sm;&2"
0FsGqFt
public synchronized int write(byte[] b,int nStart,int nLen) AF ZHS\
{ [Nr6qxWg
int n = -1; V' "p a
try{ o;M"C[
oSavedFile.write(b,nStart,nLen); / _-?NZ
n = nLen; m*|3
} {l.) *#O
catch(IOException e) 'y}l9alF
{ xKEHNgen
e.printStackTrace (); ypwVzCUG
} Duj9PV`2
8fTuae$^
Yq4_ss'nB
return n; kM*f9x
} ,'m<um
oOBN
lLxKC7b
} cgc|G
KR%p*Nh+C
HviL4iO
/* >&RpfE[
**SiteInfoBean.java ko@I]gi2
*/ P )_g t
package NetFox; 3X89mIDr
&Ph@uZ\
B-|:l7
public class SiteInfoBean { 0Q_AF`"
;:vbOG#aSN
%L}9nc%~eP
private String sSiteURL; //Site's URL [?)}0cd0
private String sFilePath; //Saved File's Path 6Y)'p .+g
private String sFileName; //Saved File's Name [ahD%UxO5
private int nSplitter; //Count of Splited Downloading File K SDo)7`
bk}.^m!
iE':ur<`
public SiteInfoBean() )}9Ef"v|
{//nSplitter的缺省值为5 [mJcc
//default value of nSplitter is 5 ~A}"s-Kq5
this("","","",5); -wvrc3F
} NwIl~FNK
`]_#_
VT?JTW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tmDI2Z%7
{ {1'XS,2
sSiteURL= sURL; iyc}a6g
sFilePath = sPath; qm4 Ejc<
sFileName = sName; ;yqJEj_m(
this.nSplitter = nSpiltter; ce.'STm=
(\e,,C%;
W=&\d`><k
} HtgVD~[]
8TD:~ee
L:IaJ?+?
public String getSSiteURL() fJn;|'H!
{ ;3h[=hyS
return sSiteURL; OvX z+C,
} Z+' 7c|a
BR8z%R
.<gAa"
public void setSSiteURL(String value) xv]P-q0
{ ':R)i.TS
sSiteURL = value; iSUn}%YFz!
} /PE3>"|wE
o_t2 Z
\kF}E3~+#
public String getSFilePath() eA$9)K1GO
{ J~V`"uo
return sFilePath; e57}.pF^
} IfF<8~~E
3:&!Q*i;
-8HIsRh
public void setSFilePath(String value) l"*qj#FD
{ ;VSHXU'H
sFilePath = value; z|=l^u6uS
} >7!4o9)c
B%6>2S=E
1?]Gl+}
public String getSFileName() w{?nX6a@p
{ Jt43+]
return sFileName; HB\<nK
} ELk$lm&@
{oy(08`6
yyPkjUy[
public void setSFileName(String value) MlkTrKdGi
{ AA;\7;k{
sFileName = value; eG72=l)Mz
} yeFt0\=H
$u|p(E:*
4Smno%jq
public int getNSplitter() <:-|>R".
{ lj/?P9
return nSplitter; i*:lZeU61
} v}Gq.(b
j/TsHJ=
-MbnYs)
public void setNSplitter(int nCount) hzg&OW=:
{ "G)-:!H
nSplitter = nCount; nmn$$=~)
} w}zl=w{G
} KV k 36;$
12gcma}
PPU,o8E+
/* kG[u$[B
**Utility.java yBXdj`bV
*/ ^:5;H=.
package NetFox; %a<N[H3NV@
SouPk/-B80
@aN<nd`q)
public class Utility { n7i;^=9mM
IFlDw}M!9
3o9`Ko0
public Utility() / *Z(;-
{ T3u%V_
)TnxsFC
0$b)@
} {-2I^Ym 5i
~=aD*v<3d
//线程睡眠 'IY?7+[
public static void sleep(int nSecond) PEW^Vl-6q
{ W&q]bi@C
try{ ` :eXXE
Thread.sleep(nSecond); %k_R;/fjW
} GM%%7^uE
catch(Exception e) DDq*#;dP
{ N&K:Jp
e.printStackTrace (); Q9tBHz
} ~>3$Id:
} B4bC6$Lg
8fKt6T
//日志 ogbLs)&+a
public static void log(String sMsg) /@gD 8
{ |G&<@8O
System.err.println(sMsg); \\AufAkJ
} ;f#%0W{":
L,*2tJcC<
tPIT+1.]z
public static void log(int sMsg) xgn@1.}G
{ ~J^Gzl
System.err.println(sMsg); !FX0Nx=oi
} 1q]V/V}
} 5, R\tJCK
r"d/9
[wWip1OR
/* coT|t T
**TestMethod.java w&jyijk(
*/ !(~eeE}|lM
package NetFox; W(Z_ac^e[
j$'L-kK+
zPEx;lO$
public class TestMethod { jku_0Q0*?
vQ>x5\r5O_
S;sggeP7,
public TestMethod() B!0o6)u'
{ ///xx/weblogic60b2_win.exe >&6pBtC_
try{ [tGAo/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D^yZ!}Kl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); HhDiGzOSi
SiteFileFetch fileFetch = new SiteFileFetch(bean); Tjma'3H*T0
fileFetch.start(); eu@hmR8T
} |s`j=<rNQI
catch(Exception e){e.printStackTrace ();} }u:@:}8K
(Gr8JpV
O]>9\!0{
} 4|YCBXWh
r1b{G%;mJ
h[b5"Uqj
public static void main(String[] args) @]P#]%^D2
{ 3}e-qFlV8,
new TestMethod(); CG*eo!Nw
} F$QN>wPpM
} B{$4s8XU
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