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)); 8bIwRVA2\
} b4HUgW3Ac
for(int i=0;i<nEndPos.length-1;i++) $-:j'e:j
{ 6$|!_94>*)
nEndPos = nStartPos[i+1]; %+,7=Wt-
} &=d0'3k>
nEndPos[nEndPos.length-1] = nFileLength; 1SYBq,[])
} 9L^:N)-
} +Y
UF ]g6u
XV> )[Nd\H
//启动子线程 P,@ :?6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $rG~0
for(int i=0;i<nStartPos.length;i++) GE{u2<%@
{ 56 raZC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TQ\\/e:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <CnTiS#
nStartPos,nEndPos,i); lZa L=HS#L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c/q -WEKL
fileSplitterFetch.start(); m|5yET
} bez_|fY{T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $WV N4fg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]7ZY|fP2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c<gvUVHIxR
nEndPos = " + nFileLength); _PR><L_
// fileSplitterFetch[nPos.length-1].start(); OAhCW*B
bq<DW/
sC=fXCGW\p
//等待子线程结束 #nS
//int count = 0; j>70AE3[8
//是否结束while循环 ~20O&2
boolean breakWhile = false; 3LaqEj
.;&1"b8G
psHW(Z8G
while(!bStop) oMj;9,WK'
{ JNYFu0
write_nPos(); 5#SD$^
Utility.sleep(500); I2$.o0=3Y
breakWhile = true; e+t2F |xDh
gVs8W3GW
g}\Yl.
for(int i=0;i<nStartPos.length;i++) oL2 a:\7
{ ATb[/=hP<R
if(!fileSplitterFetch.bDownOver) xxN=,p
{ wwtk6;8@
breakWhile = false; mz~aSbb|
break; i9FHEu_
} 0WjPo
} m:1f7Z>
if(breakWhile) ??!+2G#%!
break; ' N@1+v=
]hxE^/87
(KF=v31_m
//count++; ?u`TX_OsB
//if(count>4) IC6}s
// siteStop(); ; iK9'u
} &!lGx7zf
D6KYkN(,v
Gg3cY{7
System.err.println("文件下载结束！"); *0 0K3
} ?1z." &
catch(Exception e){e.printStackTrace ();} Y0||>LX
} n' \poB?
DhL]\ 4
'01ifA^
//获得文件长度 ,KMt9<
public long getFileSize() %S<0l@=5`l
{ cG"+n@\
int nFileLength = -1; +s}"&IV%
try{ Q599@5aS
URL url = new URL(siteInfoBean.getSSiteURL()); u5,\Kz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w1je|Oil
httpConnection.setRequestProperty("User-Agent","NetFox"); Zljj
`nxm<~-\
kAEm#oz=g
int responseCode=httpConnection.getResponseCode(); xt%-<%s%f
if(responseCode>=400) 39w|2%(O.
{ ]0VjVU-
processErrorCode(responseCode); ?~;8Y=O
return -2; //-2 represent access is error 8}&O7zO?
} )PRyDC-
c teUKK.|)
uHv9D%R
String sHeader; d{UyiZm\
nH#|]gVI
K&t+3O
for(int i=1;;i++) 4&Q.6HkL
{ O;u&>BMk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~"E@do("
//Utility.log(in.readLine()); yX}riXe
sHeader=httpConnection.getHeaderFieldKey(i); }4!R2c
if(sHeader!=null) 8u,f<XHi"a
{ E6{|zF/3'
if(sHeader.equals("Content-Length")) 5AWIk,[
{ 0$-N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cMCGaaLU
break; poqcoSL"}
} r.5}Q?
} _`/:gkZS
else 'nOc_b0
break; ltKUpRE\?
} gg>O:np8
} DA5kox&cU
catch(IOException e){e.printStackTrace ();} Z\{"/( Hi
catch(Exception e){e.printStackTrace ();} Ut;,Z
".9b}}
6]=R#d 7U
Utility.log(nFileLength); ,qS-T'[v,(
Hoaf3 `n
):@XMECa
return nFileLength; o<*H!oyP\
} m"{D}(TA
CH6^;.
fa7I6 i
//保存下载信息（文件指针位置） Pd99vq/
private void write_nPos() w&eX)!
{ vjy59m
try{ kxJ! #%w
output = new DataOutputStream(new FileOutputStream(tmpFile)); d]JiJgfa%
output.writeInt(nStartPos.length); %1uY
for(int i=0;i<nStartPos.length;i++) hrpql_9.
{ #S57SD
// output.writeLong(nPos); nM+(
output.writeLong(fileSplitterFetch.nStartPos); "t4$%7L]
output.writeLong(fileSplitterFetch.nEndPos); k^ CFu
} eIzT(3(
output.close(); vZHm'
} 35dbDgVz$
catch(IOException e){e.printStackTrace ();} jl;%?bx
catch(Exception e){e.printStackTrace ();} j4v.8;
} *C~O[:6D
R^`#xQ
S\"/=|\
//读取保存的下载信息（文件指针位置） kKU,|>3h
private void read_nPos() \/3Xb
{ VP|ga}(
try{ EkV LSur
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #K8kz
int nCount = input.readInt(); g1JBssw&m
nStartPos = new long[nCount]; }B=`nbgIG7
nEndPos = new long[nCount]; orB8q((
for(int i=0;i<nStartPos.length;i++) ;(cqaB
{ #$&!)13
nStartPos = input.readLong(); /8\gT(@
nEndPos = input.readLong(); 1epj/bB&
} 9?xMsu-H
input.close(); DYJ F6O
} -r%3"C=m
catch(IOException e){e.printStackTrace ();} +I$ k_
catch(Exception e){e.printStackTrace ();} xFU*,Y
} 'lPt.*Y<u
4ZY0!'be-R
n\f8%z
private void processErrorCode(int nErrorCode) s2-`}LL
{ VKW9Rn9Qg
System.err.println("Error Code : " + nErrorCode); wb@TYvDt
} d4Y8q1
|!VSed#FSn
`GsFvxz
//停止文件下载 Sm6hyZFy
public void siteStop() 1wX0x.4d
{ R;2tb7o
bStop = true; }%K)R5C
for(int i=0;i<nStartPos.length;i++) =-XI)JV#
fileSplitterFetch.splitterStop(); 0{0|M8
jpcbW
qJ).;S{AAt
} |{ E\ 2U
} T%
//负责部分文件的抓取 -e6~0%X
**FileSplitterFetch.java K:PPZ|
*/ ]?n)!u
package NetFox; !"w1Pv,
?!R Z~~d
C5Fk>[fS
import java.io.*; >k gL N
import java.net.*; |D `r o
J7FCW^-`3
~)';[Ha
public class FileSplitterFetch extends Thread { 5l"/lGw
W`}C0[%VW
@D<q=:k
String sURL; //File URL mJBvhK9%
long nStartPos; //File Snippet Start Position s68&AB
long nEndPos; //File Snippet End Position %E\&9,
int nThreadID; //Thread's ID L0\97AF
boolean bDownOver = false; //Downing is over a1lF8;[
boolean bStop = false; //Stop identical N*~G ]
FileAccessI fileAccessI = null; //File Access interface {U:c95#.!S
qDR`)hle
*>x~`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q8U*
{ RP}.Ei
this.sURL = sURL; ?]i.Zi\[f
this.nStartPos = nStart; so~vnSQ!x
this.nEndPos = nEnd; 4CR.=
nThreadID = id; {0J TN%e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9,h'cf`F
} ?T+Uu
fv1pA+zN[
6$"gm$3O]
public void run() o)_;cCr)q
{ ?LP&VU1
while(nStartPos < nEndPos && !bStop) 7_,)"J2^
{ wB(A['k
uWs5+
>EQd;Af
try{ @lo6?9oNo
URL url = new URL(sURL); 4a'GWzUtS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3B }Oy$p
httpConnection.setRequestProperty("User-Agent","NetFox"); $ b Q4[
String sProperty = "bytes="+nStartPos+"-"; !}u'%
httpConnection.setRequestProperty("RANGE",sProperty); yQkj4v{
Utility.log(sProperty); y#[PQT
obUX7N
i3T]<&+j5
InputStream input = httpConnection.getInputStream(); jOuz-1x,&
//logResponseHead(httpConnection); }R.<\
_1D'9!+
p=T,JAIt
byte[] b = new byte[1024]; sq6|J])GgU
int nRead; "xS?#^a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m791w8Vr
{ 9UD~$_<\
nStartPos += fileAccessI.write(b,0,nRead); SKx&t-
//if(nThreadID == 1) =d#3& R]p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %xE9vN;
} P{ AJH1
2jQ|4$9j
h=uv4&
Utility.log("Thread " + nThreadID + " is over!"); OidF{I*O
bDownOver = true; wyqXD.of
//nPos = fileAccessI.write (b,0,nRead); 3Lx]-0h
} S|U/m m
catch(Exception e){e.printStackTrace ();} ^rd]qii"
} &%QtUPvr9
} BdHLow
'%&i#Eb
q4)8]Y2
//打印回应的头信息 V#!ftu#c?
public void logResponseHead(HttpURLConnection con) \ "193CW!
{ Vj^<V|=
for(int i=1;;i++) e<_p\LiOS
{ ocwh*t)<k
String header=con.getHeaderFieldKey(i); wIi_d6?
if(header!=null) 2=pVX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :-xF=Y(;
Utility.log(header+" : "+con.getHeaderField(header)); S<Zb>9pl
else w!{g^*R+!
break; !(=bH"P
} b[<Q_7~2
} v#EXlpS
=i jGB~
r"s <;
public void splitterStop() P$MAURFm
{ Yrb[:;Y
bStop = true; a=LjFpv/]
} rYI9?q
^:Vwblv(
tWkD@w`Lnn
} [ Fid
+R}(t{b#
>mzK96
/* a%2r]:?^?
**FileAccess.java K-VNU
*//文件访问(定位，写) SooSOOAx[
package NetFox; Z/=x(I0
import java.io.*; Pyc/6~?
I~lX53D
ndRy&[f7
public class FileAccessI implements Serializable{ ]<D9Q>
RFyeA. N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *Q bPz4,"
RandomAccessFile oSavedFile; ^J0*]k%
long nPos; PfTjC"`,
D0(QZrVa
Y$8 >fv
public FileAccessI() throws IOException 3RpDIl`0
{ ~Ein)5
this("",0); U[5
} (r_xs
,]e!OZ[$m
/M>8ad
public FileAccessI(String sName,long nPos) throws IOException M~Tq'>Fn
{ <'H^}gQow
oSavedFile = new RandomAccessFile(sName,"rw"); #&vP(4p
this.nPos = nPos; Yrp WGK520
oSavedFile.seek(nPos); qv<[f=X9|
} oy90|.]G
3{o5AsVv
hamn9
public synchronized int write(byte[] b,int nStart,int nLen) vluA46c
{ BR5r K
int n = -1; )cc:Z7p
try{ eaQ)r?M
oSavedFile.write(b,nStart,nLen); Ct[{>asun
n = nLen; ^S*~<0NQ'
} > t*+FcD
catch(IOException e) kDuN3
{ il=y m
e.printStackTrace (); F0 WM&{v
} |]`\ak
oGpyuB@A/
wJA`e)>
return n; qYj EQz
} X-Y:)UT
0sW=;R2
OgjSyzc
} /5:C$ik
Sw~jyUEr
|<&9_Aq_
/* [>xwwm
**SiteInfoBean.java 2<Lnfc<^k
*/ 3A2X1V"
package NetFox; G"&9u2k
X $LX;Lv
Y85M$]e,
public class SiteInfoBean { -7)%J+5
'r6s5 WC
MKSiOM
private String sSiteURL; //Site's URL fvKb0cIx]
private String sFilePath; //Saved File's Path nff&~lwhZ
private String sFileName; //Saved File's Name F)KUup)gc
private int nSplitter; //Count of Splited Downloading File 9u";%5 4
dM"Suw
g+h)s!$sB
public SiteInfoBean() #|76dU
{//nSplitter的缺省值为5 xwG=&+66
//default value of nSplitter is 5 uxF88$=!t
this("","","",5); Ht,_<zP;
} qh;ahX~
4PUSFZK?
v5U\E`)s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5tI4m#y2
{ B:dk>$>uQ
sSiteURL= sURL; ! 9B| `
sFilePath = sPath; D. !m*oq
sFileName = sName; 4;@|tC|u
this.nSplitter = nSpiltter; i_?";5B"
y\&GPr
C=L_@{^Rgb
} =E@wi?
lquY_lrri
i{zg{$U
public String getSSiteURL() BG!;9Z{u
{ w7NJ~iy
return sSiteURL; ed$g=qs>
} kylR)
7:x%^J+
B,?Fjot#m
public void setSSiteURL(String value) uKF?UXc
{ HlEp Dph%
sSiteURL = value; e<s56<3j
} 1'tagv?
'3SS%W
u*u>F@C8
public String getSFilePath() 8%OS ,Z
{ p@`rBzGp
return sFilePath; w8E6)wF=7
} e _\]Q-
&U\Xy+
!l!^`c
public void setSFilePath(String value) (.TkvUj`
{ -#srn1A>
sFilePath = value; [V'3/#Z
} tpw0j CVu
&>kklP
~7aBli=
public String getSFileName() ~#3h-|]*
{ UO(B>Abp
return sFileName; MJ^NRT0?b
} 5|2v6W!e
[9S\3&yoh
No8~~
public void setSFileName(String value) PGZ.\i
{ kb<Nuw
sFileName = value; u=B_cA}:
} x9}D2Ui
:<Z*WoEmt
n|`L>@aw,
public int getNSplitter() ;n?72&h
{ jR<yV
return nSplitter; lN94 b3_W
} - Z?rx5V;t
ldcYw@KQ
}}Ah-QU
public void setNSplitter(int nCount) DueQ1+ P
{ 2Wz/s 0`
nSplitter = nCount; Hm2}xnY
} 41 sClC"
} ~J1;Z0}#
|0:&dw?*!
Ep-{Ew{T_=
/* v w$VRPW
**Utility.java A[L+w9
*/ pC,MiV$c"
package NetFox; "-JJ6Bk
pnin;;D*
\zA$|) x
public class Utility { O[[:3!6q
h_6QVab@
#iD5& klo\
public Utility() UKyOkuY:w
{ rQT@:$)
Hb5^+.xur
V#jFjObTN
} 9u<4Q_I`
=)5eui>{
//线程睡眠 Ro :/J
public static void sleep(int nSecond) CpHF3o`Z6
{ H?tonG.^(
try{ Kd}cf0
Thread.sleep(nSecond); R?3^Kx
} S N_!o2F2
catch(Exception e) ^S!^$d*
{ sl^i%xJ|l'
e.printStackTrace (); ~5$V8yfx h
} g2%&/zq/
} X~XpX7d!
5`,qKJ
//日志 + 5E6|
public static void log(String sMsg) %.,-dV'
{ J^[>F{8!n
System.err.println(sMsg); QUd`({/@:
} ]5IG00`
tU7,nE>p
A2 r1%}{
public static void log(int sMsg) )@)wcf!b
{ FNlzpCT~L
System.err.println(sMsg); ?_36uJo}
} "e62g
} SPKGbp&
$ hwJjSZ0
"l~wzPY)
/* nokk!v/
**TestMethod.java v>zeK
*/ I$sJ8\|gw'
package NetFox; !7ct=L
+r[u4?
bTB/M=M
public class TestMethod { 0-#SvTf>;:
@? 4-
K~"uZa^s
public TestMethod() Q#NXJvI
{ ///xx/weblogic60b2_win.exe B0I(/ 7
try{ 6wH]W+A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O o9 ePw7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A-<\?13uW
SiteFileFetch fileFetch = new SiteFileFetch(bean); CuRYtY@9
fileFetch.start(); r@L19d)J
} Q?Vq/3K;
catch(Exception e){e.printStackTrace ();} +')\,m "z
Sz4YPl
)70-q yA
} `*nVLtT Y
WP-?C<Iw
N{v <z 6
public static void main(String[] args) 6jjmrc[#}X
{ >#).3
new TestMethod(); (Qmpz
} ju#/ {V;D
} GkqKIs
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