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)); !U@?Va~Zn
} E,#J\)'z
for(int i=0;i<nEndPos.length-1;i++) `+!GoXI
{ 0wzq{~\{=_
nEndPos = nStartPos[i+1]; S'I{'jP5
} +;}XWV
nEndPos[nEndPos.length-1] = nFileLength; f8Xe%"<
} s57-<&@J9
} jZm57{C#*?
%mhnd):
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//启动子线程 NY5?T0/[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K,>D%mJ
for(int i=0;i<nStartPos.length;i++) ?5%|YsJP_
{ {&'u1yR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %#.HFK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4DL;/Z:
nStartPos,nEndPos,i); .Jt&6N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =Of!1TR(
fileSplitterFetch.start(); *N0R3da
} b ;Vy=f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $?l?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ba$Ibq,r/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CL^MIcq?
nEndPos = " + nFileLength); FuZ7xM,
// fileSplitterFetch[nPos.length-1].start(); ~$0Qvyb>
V4RtH
JZ[~3swR
//等待子线程结束 QOECpk-
//int count = 0; ~ituPrH%<
//是否结束while循环 `};8
boolean breakWhile = false; 5N:THvh6o
%5=XszS
DcN s`2
while(!bStop) p",HF%
{ t}E1NXW
write_nPos(); 2EubMG
Utility.sleep(500); 3 ;F=EMz{
breakWhile = true; {YCquoF
hi>sDU<x
<}c`jN!z.
for(int i=0;i<nStartPos.length;i++) <y(uu(c
{ F<y5zqGy@
if(!fileSplitterFetch.bDownOver) ELp @/c=Wr
{ ^/Id!Y7
breakWhile = false; ]_S&8F}|
break; =o5ZcC
} +"!,rZ7,A
} _5^p+
if(breakWhile) V`KXfY
break; &#'[]V%^F
4#?OxvH
!b"#`O%`
//count++; E%M~:JuKd?
//if(count>4) cH()Ze-B
// siteStop(); ;r[@;2p*(
} dkuB{C,
;4E0%@R
q%=`PCty
System.err.println("文件下载结束！"); S6 F28 d[j
} nn@"68]g
catch(Exception e){e.printStackTrace ();} mbBd3y
} 5$Yt@8;
Aw)='&;^z
6]dK,
//获得文件长度 8X`Gm!)
public long getFileSize() L;=<d
{ Gw6*0&3')
int nFileLength = -1; JVAJLq
try{ (]Z%&>*
URL url = new URL(siteInfoBean.getSSiteURL()); iHo2=Cz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &|7pu=
httpConnection.setRequestProperty("User-Agent","NetFox"); )1a3W7
X I\zEXO
{]~b^=qE$
int responseCode=httpConnection.getResponseCode(); uE~? 2G
if(responseCode>=400) odPq<'V|AY
{ [-cYFdt"V
processErrorCode(responseCode); +*3\C!
return -2; //-2 represent access is error 317Lv \[
} vcsi@!
M0<gea\ =
iWu$$IV?-
String sHeader; 2G8f4vsC[
o$>A;<
J7BfH,o
for(int i=1;;i++) Ij hC@5qk
{ ~A+DH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ti }Ljp^O
//Utility.log(in.readLine()); bWK}oYB*
sHeader=httpConnection.getHeaderFieldKey(i); F>,kKR-
if(sHeader!=null) Z 4uft
{ _dY6Ip%
if(sHeader.equals("Content-Length")) 4r!8_$fN?G
{ y&NO[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <qs>c<Vj
break; =$UDa`}D
} ajuwP1I
} Mg]q^T.a
else S(jbPQT
break; }E+}\&
} Bry\"V"'g
} %N@454enH
catch(IOException e){e.printStackTrace ();} 8V%(SV
catch(Exception e){e.printStackTrace ();} c *(]pM
N=&~3k
RSG\3(
Utility.log(nFileLength); 89:Ys=
f5+a6s9
NaC^q*>9
return nFileLength; Wa%Zt*7
} m]JZ@
oJy]n9
4f<%<Z
//保存下载信息（文件指针位置） 'u$e2^
private void write_nPos() 5An|#^]
{ MzRURH,
try{ MNNPBE
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sc;WraEn2
output.writeInt(nStartPos.length); FA?xp1E
for(int i=0;i<nStartPos.length;i++) U@dztX@u
{ CF3Z`xD
// output.writeLong(nPos); JK.lL]<p i
output.writeLong(fileSplitterFetch.nStartPos); Q*mzfsgr
output.writeLong(fileSplitterFetch.nEndPos); q bb:)>
} w `6qT3v
output.close(); ZKyK#\v<
} #L.fGTb
catch(IOException e){e.printStackTrace ();} `<2y [<y
catch(Exception e){e.printStackTrace ();} Tm@d;O'E1
} VL"!.^'c
#r; 'AG
SLO;c{EFH
//读取保存的下载信息（文件指针位置） /u{ 9UR[g
private void read_nPos() ymSGB`CP
{ A.m#wY8
try{ VZ{aET!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j8?z@iG
int nCount = input.readInt(); 4lH$BIAW
nStartPos = new long[nCount]; "BZ6G`
nEndPos = new long[nCount]; RG-pN()
for(int i=0;i<nStartPos.length;i++) $QmP' <
{ S P)$K=
nStartPos = input.readLong(); =1fO"|L
nEndPos = input.readLong(); S/& _
} 0f/=C9L
input.close(); ma>{((N
} "0Uh(9Fv
catch(IOException e){e.printStackTrace ();} ?as)vYP
catch(Exception e){e.printStackTrace ();} KHKf+^uu
} x(h(a#,r
HJ]\VP9Zb
i/R8Gb
private void processErrorCode(int nErrorCode) O`U&0lKi'
{ f m.-*`ax
System.err.println("Error Code : " + nErrorCode); M0DdrL/ L
} utKtxLX"
'x BBQP
ZurQr}
//停止文件下载 4]RGLN
public void siteStop() }OgzSnR
{ IF%^HK@
bStop = true; 7(lR$,bE;=
for(int i=0;i<nStartPos.length;i++) *;. l/
fileSplitterFetch.splitterStop(); \2)a.2mAz
Gd1%6}<~
s2L|J[Y"s
} ;AK;%
} g2.%x\d
//负责部分文件的抓取 " &'Jw
**FileSplitterFetch.java 'F^nW_ryW
*/ :ak D
package NetFox; NJSzOL_
sF^3KJ|
/~V.qisZ
import java.io.*; %m1k^
import java.net.*; y-O# +{7
1[o] u:m9U
n}PK0
public class FileSplitterFetch extends Thread { {C Qo}@.7
+ia F$
!fr /WxJ
String sURL; //File URL .g_BKeU
long nStartPos; //File Snippet Start Position Lc(D2=%
long nEndPos; //File Snippet End Position dHc38zp
int nThreadID; //Thread's ID S3]Cz$
boolean bDownOver = false; //Downing is over s`M[/i3Nm
boolean bStop = false; //Stop identical Au &NQ+
FileAccessI fileAccessI = null; //File Access interface Ffk$8"
2 |w;4
GJW+'-f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tmiRv.Mhn<
{ "I?sz)pxG
this.sURL = sURL; 1XQJ#J1/
this.nStartPos = nStart; ]8KAat~J
this.nEndPos = nEnd; Gjq:-kX\
nThreadID = id; @gc lks/M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oomB/"Z
} #$7 z
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public void run() pe=Ou0
{ Yf >SV #
while(nStartPos < nEndPos && !bStop) Bt4 X
{ ~(kIr?^
[vb>5EhL!
/*s:ehj
try{ L8n1p5gx3
URL url = new URL(sURL); FDM&rQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7q?u`3l
httpConnection.setRequestProperty("User-Agent","NetFox"); 4mSL*1j
String sProperty = "bytes="+nStartPos+"-"; vUl5%r2O4
httpConnection.setRequestProperty("RANGE",sProperty); HubSmbS1
Utility.log(sProperty); C-4NiXa
pisjfNT`o
[?$ZB),L8
InputStream input = httpConnection.getInputStream(); 0 ;kcSz
//logResponseHead(httpConnection); iaBy/!i
2MwRjh_
aZ^P*|_K3
byte[] b = new byte[1024]; |E$Jt-'
int nRead; 5&q@;vR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {bnNY
{ o.U$\9MNP
nStartPos += fileAccessI.write(b,0,nRead); 5\1Z"?
//if(nThreadID == 1) CZyOAoc<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^G%Bj`%
} $by-?z((
CL%?K<um
/'?Fz*b
Utility.log("Thread " + nThreadID + " is over!"); J&UFP{)
bDownOver = true; |1J=wp)#
//nPos = fileAccessI.write (b,0,nRead); +RS>#zd/=
} > ^fY`x,
catch(Exception e){e.printStackTrace ();} R< @o]p
} e:}8|e~T
} Q#P=t83
qR0V\OtgY~
$~c?qU
//打印回应的头信息 3?I^D /K^
public void logResponseHead(HttpURLConnection con) x'*,~u
{ +F q`I2l|
for(int i=1;;i++) \ &1)k/
{ SvC|"-[mJ
String header=con.getHeaderFieldKey(i); F_;oZ
if(header!=null) "8|y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oZ95)'L,
Utility.log(header+" : "+con.getHeaderField(header)); 7><ne|%
else CK[2duf^~
break; B;tU+36nM
} Cd)e_&
} Et~b^8$>
FrD.{(/~
f'aQ T
public void splitterStop() ']^e,9=Q
{ u%?u`n2'
bStop = true; e"(l
} 5zG6V2
i$[wgvJIV
W Da;wt
} I7b(fc-r
]$(::'pmK
,t5X'sY L
/* *9)7.}uY
**FileAccess.java >kOca
*//文件访问(定位，写) k7P~*ll$
package NetFox; aVvi_cau
import java.io.*; p'1n'|$e
p#~'xq
m&o}qzC'y
public class FileAccessI implements Serializable{ mLX1w)=r
VpSk.WY/ e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ie+&@u
RandomAccessFile oSavedFile; *>%34m93
long nPos; ):?ype>
p.i$[6M
T.="a2iS2
public FileAccessI() throws IOException hkSpG{;7
{ K[)N/Q
this("",0); nW+rJ
} m! &bK5+*
Kv"e\ E
b1{~j]"$L
public FileAccessI(String sName,long nPos) throws IOException Zy@35;r
{ %Q"zU9
oSavedFile = new RandomAccessFile(sName,"rw"); 0?l|A1I%
this.nPos = nPos; _i~n!v
oSavedFile.seek(nPos); ]YkF^Pf!v
} [9UKVnX.V
g6EdCG.V
xG0IA 7
public synchronized int write(byte[] b,int nStart,int nLen) 8,2l >S
{ Z:aDKAboU
int n = -1; EAo7(d@
try{ 9oS\{[x.
oSavedFile.write(b,nStart,nLen); b6_*ljM
n = nLen; ncJ}h\:Sk
} AC3K*)`E
catch(IOException e) (u85$_C
{ K1uN(T.Ju
e.printStackTrace (); A@*P4E`xp
} w_G/[R3
,$5;
nS[0g^}
return n; ZmO/6_nU?
} ?6Cbx6
uoFH{.)
#/sKb2eQ
} ba|x?kz
)/2* <jr
jo=XxA
/* y=YD4m2W
**SiteInfoBean.java &Th/Qv}[
*/ td4*+)'FY
package NetFox; !JUXq
$/,qw
F0:Fv;
public class SiteInfoBean { '[JrP<~^o
"[@-p
7;KmJ}$
private String sSiteURL; //Site's URL |Z6rP-
private String sFilePath; //Saved File's Path isHa4 D0
private String sFileName; //Saved File's Name oju/%ieh
private int nSplitter; //Count of Splited Downloading File VY<v?Of i-
: QSlctW
CZE5RzG
public SiteInfoBean() `d6 {Tli
{//nSplitter的缺省值为5 ~$#DB@b
//default value of nSplitter is 5 f[ GH
this("","","",5); MUz.-YRt
} ]tH/87qJ
btw_k+Fh
+^<CJNDL9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z<En3^j`
{ Jjik~[<q:
sSiteURL= sURL; 2j-|.l c
sFilePath = sPath; ] =b?^'
sFileName = sName; :Y y+%
this.nSplitter = nSpiltter; al=Dy60|z
bj(U?$
eJE?H]
} O(,Ezyx
ru3nnF_I
s['F?GWg
public String getSSiteURL() ?nrd$,
{ ^C>i(j&
return sSiteURL; Lcplc"C
} ?v#t{e0eQ
MR%M[SK1
Rb<aCX
public void setSSiteURL(String value) 3s\2 9gq
{ hnL"f[p@gC
sSiteURL = value; LYGFEjS[
} V!c{%zd
{"y{V
j9%u&
public String getSFilePath() G9z Q{E
{ \%&QIe;:k
return sFilePath; B9iH+ ]W
} :g'"*VXYB
z1f~:AdL
L|S#(0
public void setSFilePath(String value) ]N-K`c]
{ |k)h' ?
sFilePath = value; F0bmGDp@-
} (Z)
B^U5=L[:p
Ha$|9li`
public String getSFileName() ?ZdHuuDN~
{ f!P.=Qo[=
return sFileName; +%eMm.(
} ,V)yOLApVj
vkE6e6,Qc
nE]R0|4h
public void setSFileName(String value) $k@reN9
{ 9XF+? x
sFileName = value; P~;NwHZ?k
} mn*.z!N=
q ]rsp0P2
+F&w~UT
public int getNSplitter() |GL#E"[&'
{ 3RscuD&
return nSplitter; /QHvwaW[
} p}R)qz-=5U
mY(~94{d
@s2z/h0H
public void setNSplitter(int nCount) y M , hF
{ |w6:mtaS
nSplitter = nCount; azPFKg+
} @]WN|K
} M<"&$qZ$R
D?qA aq&4
)Y Qtrc\91
/* qQ/j+
**Utility.java $>OWGueq64
*/ :uZcN
package NetFox; HkJ$r<J2
SR%h=`t
O9p8x2
public class Utility { s~]Ri:7~
wjoxfPnf
(J\"\#/d
public Utility() vhTte |(
{ 6T"[M
cQu1WgQ G
a[xEN7L~4D
} YX18!OhQ
v)d\ 5#7
//线程睡眠 ,S:g5n>M
public static void sleep(int nSecond) Jmf&&)p
{ TaG'?
try{ [#)-F_S
Thread.sleep(nSecond); |6"zIHvtc
} 6jRF[N8
catch(Exception e) xO'1|b^&
{ /=lrdp!a
e.printStackTrace (); ;,JCA# N
} puL1A?Y8UM
} |0B h
bf'@sh%W
//日志 /AjGj*O
public static void log(String sMsg) Q6RBZucv
{ /tJJ2 =%l
System.err.println(sMsg); Ca*^U-
} #J, `a.
QlSZr[^v
9W5vp:G
public static void log(int sMsg) E{_p&FF
{ jv5p_v4%O
System.err.println(sMsg); u(\b1h n
} #8%Lc3n
} '?v.O}
^B1Q";# B^
+*DXzVC
/* .B"h6WMz
**TestMethod.java W _yVVr
*/ (VWTYG7
package NetFox; U:#9!J?41
4rw<C07Z
^WVH z;
public class TestMethod { (4>k+ H
j Bl I^
zK}$W73W^
public TestMethod() !HY+6!hk
{ ///xx/weblogic60b2_win.exe 1$q SbQ
try{ x a7x 2]~-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `V$i*{c:#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FlrLXTx0
SiteFileFetch fileFetch = new SiteFileFetch(bean); X@\rg}kP
fileFetch.start(); x!tCK47Yq
} zo7Hm]W`
catch(Exception e){e.printStackTrace ();} rts@1JY[
s0E:hn:
&xj?MgdNL
} R% l=NHB}
= =cAL"Z
8qrE<RHU@
public static void main(String[] args) i?A4uyYwS
{ ]}w~fjq
new TestMethod(); {Tm31f(oD
} ](aXZ<,
} DdN{=}A
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