http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); /?sV\shy
} [#:k3aFz
for(int i=0;i<nEndPos.length-1;i++) Ev%\YI!MaY
{ F<$&G'% H
nEndPos = nStartPos[i+1]; am}zOr\
} F}X_I
nEndPos[nEndPos.length-1] = nFileLength; P1t5-q
} =["GnL*!0
} [Mi~4b
wQ5__"D
yC[}gHv
//启动子线程 Oe$C5KA>LW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nx99dr
for(int i=0;i<nStartPos.length;i++) 6 Qmtb2
{ gisZmu0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /=N`P &R#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c&Dy{B!
nStartPos,nEndPos,i); {}z7N~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xRfX:3
fileSplitterFetch.start(); tm$3ZzP4
} V|7 cdX#H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SC#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >a<;)K^1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q bo`E!K
nEndPos = " + nFileLength); u%FA.
// fileSplitterFetch[nPos.length-1].start(); HkrNt/]
BEw(SQH
R#0UwRjeF
//等待子线程结束 %n^]1R#
//int count = 0; #r\uh\Cy
//是否结束while循环 fIu/*PFPVY
boolean breakWhile = false; u7S7lR"lxW
o\N),;LM
2n\EZ
while(!bStop) n'SnqJ&}
{ $3So`8Bm[$
write_nPos(); l{<@[foc
Utility.sleep(500); u!O)\m-
breakWhile = true; +:b|I'S
hGsYu)
},l3N K
for(int i=0;i<nStartPos.length;i++) }q^CR(h (R
{ MD+Q_
if(!fileSplitterFetch.bDownOver) +7=3[K
{ B9]KC i
breakWhile = false; (uSfr]89'
break; S;Vj5
} [ACa<U/
} um/iK}O
if(breakWhile) &W1cc#(
break; r'&VH]m
;X8eZQ
4XRVluD%W.
//count++; a$ Z06j
//if(count>4) =cxjb,r
// siteStop(); [L:,A{rve
} ,+WDa%R
oYW:ptJ
V[#jrwhA
System.err.println("文件下载结束！"); 7a2uNt,X
} ]'hz+V31%
catch(Exception e){e.printStackTrace ();} biQDupTz
} D_g+O"];P
]`LMyt0
.RdnJ&K*
//获得文件长度 vForj*Xo
public long getFileSize() b^0=X!bg
{ q%nWBmPZ~y
int nFileLength = -1; {Wt=NI?Ow
try{ 7"1M3P5*8
URL url = new URL(siteInfoBean.getSSiteURL()); gkDB8,C<j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XOU 9r(
httpConnection.setRequestProperty("User-Agent","NetFox"); 4h-tR
{D$+~lO
+5voAx!
int responseCode=httpConnection.getResponseCode(); hDCR>G
if(responseCode>=400) |Gz(q4
{ ~OXPn9qPp
processErrorCode(responseCode); MFRM M%`
return -2; //-2 represent access is error }}<^fM
} s$A|>TOY
WOh?/F[@u
J%{>I
String sHeader; Y-v6xUc{F
(m13 ong
`j9 ;9^
for(int i=1;;i++) DKR2b`J
{ Yf1?3(0O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >o.4sN@
//Utility.log(in.readLine()); T< D&%)
sHeader=httpConnection.getHeaderFieldKey(i); ta%yQd7
if(sHeader!=null) u{J$]%C
{ F8nR.|
if(sHeader.equals("Content-Length")) W2'u]1bs
{ &=~Jw5WK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f-^JI*hj
break; #mFIZMTRd
} J.$N<.
} EjrK.|I0
else W|4:3c4
break; R10R,*6>
} ;O+= 6>W
} nH_M#
catch(IOException e){e.printStackTrace ();} qf;x~1efC4
catch(Exception e){e.printStackTrace ();} 2)-Umq{]{
',P$m&z
OQ&l/|{O0?
Utility.log(nFileLength); 0.+MlyA
0-6rIdDTM
:pq+SifP
return nFileLength; -e(e;e
} 6o6I]QL
n86LU Sj5
!cW6dc^
//保存下载信息（文件指针位置） .kcyw>T`I
private void write_nPos() }Y:V&4DW
{ W^k95%zBM
try{ fS?}(7
output = new DataOutputStream(new FileOutputStream(tmpFile)); \,D>zF
output.writeInt(nStartPos.length); a]]eQ(xQ
for(int i=0;i<nStartPos.length;i++) sFt"2TVr3
{ l|v`B6(
// output.writeLong(nPos); S"HdjEF7\
output.writeLong(fileSplitterFetch.nStartPos); [>![ViX
output.writeLong(fileSplitterFetch.nEndPos); lha)4d
} #x*\dL
output.close(); ~bf4_5
} H%pD9'q~
catch(IOException e){e.printStackTrace ();} e>0gE`8A
catch(Exception e){e.printStackTrace ();} DaP,3>M
} AT%6K.
42M_ %l_
41g "7Mk
//读取保存的下载信息（文件指针位置） CVE(N/&b
private void read_nPos() bI+/0Xx
{ &n9&k Em
try{ ,Wv+Ek
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T[Lz4;TRk5
int nCount = input.readInt(); [n4nnmM
nStartPos = new long[nCount]; Wz%H?m:g#
nEndPos = new long[nCount]; jh(T?t$&
for(int i=0;i<nStartPos.length;i++) jIEntk
{ G>=Fdt7Oc
nStartPos = input.readLong(); /g$G G9
nEndPos = input.readLong(); L>LIN 1A
} U$|q]N
input.close(); PzOnS
} ;6:9EEd
catch(IOException e){e.printStackTrace ();} bMn)lrsX
catch(Exception e){e.printStackTrace ();} -U*J5Q
} SSxp!E'
,.Lwtp,n
;.'?(iEB
private void processErrorCode(int nErrorCode) 9TX2h0U?
{ LAkBf
System.err.println("Error Code : " + nErrorCode); PriLV4?
} FY<Q|Ov
4M#i_.`z
h+=IxF4
//停止文件下载 hjyM xg;Q?
public void siteStop() By waD?
{ %_."JT$v{
bStop = true; "}MP{/
for(int i=0;i<nStartPos.length;i++) {]2^b)
fileSplitterFetch.splitterStop(); 47N,jVt4
_K}q%In
nrHC;R.nE
} `WIZY33V
} , #=TputM
//负责部分文件的抓取 9#TD1B/
**FileSplitterFetch.java @R%*;)*F
*/ ~7 `,}) d
package NetFox; G9NI`]k
n]df)a
"iTjiH)Q(
import java.io.*; R2v9gz;W
import java.net.*; !( >U3N
LaO8)lqR
?a#Gn2
public class FileSplitterFetch extends Thread { _V4O#;%?
,Kl:4 Tv
<rtKPlb//
String sURL; //File URL :.4O Hp1
long nStartPos; //File Snippet Start Position T%% 0W J
long nEndPos; //File Snippet End Position 9dq"x[
int nThreadID; //Thread's ID 6@TU9AZS`
boolean bDownOver = false; //Downing is over A|GtF3:G
boolean bStop = false; //Stop identical ]!ox2m_U
FileAccessI fileAccessI = null; //File Access interface XwUa|"X6
?r KbL^2
10fxK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D'<L6w`
{ R\|,GZ!`+
this.sURL = sURL; 1~t.2eUG
this.nStartPos = nStart; ;89kL]
this.nEndPos = nEnd; 8T1zL.u>q
nThreadID = id; VcGl8~#9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vn+XY=Qnr
} (P`=9+
:h5G|^
$m;`O_-T
public void run() y{/7z}d
{ 'y\Je7
while(nStartPos < nEndPos && !bStop) ?HJh;96B
{ +l^tT&s;f
5CZyA`3V^5
]Cj@",/3#
try{ o`QNZN7/}
URL url = new URL(sURL); VE-l6@`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h~7#$i
httpConnection.setRequestProperty("User-Agent","NetFox"); pd:7K'yaw
String sProperty = "bytes="+nStartPos+"-"; kV+^1@"
httpConnection.setRequestProperty("RANGE",sProperty); Wk\(jaL%
Utility.log(sProperty); GA[Ebzi
M#; ks9
@Wc5r#
InputStream input = httpConnection.getInputStream(); .6P.r}
//logResponseHead(httpConnection); YZ5,K6u
?OLd }8y
W?5')
byte[] b = new byte[1024]; 5afD;0D5TI
int nRead; R|n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (/uAn2
{ [EDX@Kdq)
nStartPos += fileAccessI.write(b,0,nRead); BbI%tmA7
//if(nThreadID == 1) :a6LfPEAX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d!E_EoOi
} sSZ)C|Q
H0;Iv#S!
7Y9#y{v1
Utility.log("Thread " + nThreadID + " is over!"); H}$7c`;q
bDownOver = true; &J)<1!|
//nPos = fileAccessI.write (b,0,nRead); _;BwP
} 1(-!TJ{
catch(Exception e){e.printStackTrace ();} pASX-rb
} 9a=Ll]=\
} !\X9$4po@
x=t(#R m
3Do0?~n
//打印回应的头信息 >x{("``D0y
public void logResponseHead(HttpURLConnection con) 2 ^m}5:0
{ 6@s!J8!
for(int i=1;;i++) f^FFn32u
{ 7pm'b,J<
String header=con.getHeaderFieldKey(i); r }lGcG)
if(header!=null) &]DB-t#\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?qNU*d
Utility.log(header+" : "+con.getHeaderField(header)); hI'WfF!X
else !l9{R8m>eJ
break; pcy;]U?
} xj3qOx$
} WeM38&dWY
kJJT`Ba&/
+4s]#{mP
public void splitterStop() $Z:O&sD{
{ s0/O/G?
bStop = true; $D1ha CL
} 23wztEp{a
qD{1X25O
1uAjy(y
} :~otzI4%!
wb0$FZzh
D5,]E`jwu
/* oZa'cZNs
**FileAccess.java 'OsZD?W{
*//文件访问(定位，写) 8M99cx*K
package NetFox; wM+1/[7
import java.io.*; ^.6[vmmq
JM3[ yNSN@
w}ji]V}
public class FileAccessI implements Serializable{ Zz0bd473k?
&BRk<iwV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L[x`i'0B
RandomAccessFile oSavedFile; 9MMCWMV
long nPos; G&ck98
0 0N[ :%
.xN<<+|_v'
public FileAccessI() throws IOException AJ\&>6GZ(b
{ zmo2uUEd
this("",0); $-}&RW9
} %T({;/
IrMHAM5K
=Kd'(ct
public FileAccessI(String sName,long nPos) throws IOException +<a\0FsD
{ jE*{^+n
oSavedFile = new RandomAccessFile(sName,"rw"); o;$xN3f,
this.nPos = nPos; 'JOUx_@z
oSavedFile.seek(nPos); ;7'O=%
} $Zu?Gd?
Ymz/:
gJQ#j~'
public synchronized int write(byte[] b,int nStart,int nLen) :W.H#@'(
{ -G(me"Cu
int n = -1; .nPOjwEx&Y
try{ JOJ.79CT
oSavedFile.write(b,nStart,nLen); XQo\27Fo
n = nLen; YO$Ig:a#
} /eV)5`V
catch(IOException e) 'Aq^z%|
{ P([!psgu
e.printStackTrace (); 5#GMp
} C%z)D1-
#`VAw ) eV
;z'&$#pA
return n; Sq5,}oT_{j
} \Y4(+t=4
h.edb6
TTXF r
} $ VT)
.C'\U[A{
L/i'6(="
/* z@,pT"rb
**SiteInfoBean.java 1SExlU
*/ 7kLurv
package NetFox; #_DpiiS,.Q
Nx 42k|8
g88k@<Y
public class SiteInfoBean { 0t7N yKU
p*Z<DEh#
=-r"@2HBq
private String sSiteURL; //Site's URL if*V-$[I
private String sFilePath; //Saved File's Path G"/;Cq=t
private String sFileName; //Saved File's Name 2P"643tz
private int nSplitter; //Count of Splited Downloading File LKM018H>
JWNN5#=fQ
WZ'<iI
public SiteInfoBean() Jh-yIk
{//nSplitter的缺省值为5 E=I'$*C\D
//default value of nSplitter is 5 ]3 "0#Y
this("","","",5); w){B$X
} xrf|c
LeCc`x,5
rS [4Pey
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y/sav;
{ 'gY?=,dF>
sSiteURL= sURL; "Hw%@]#
sFilePath = sPath; RdX+:!lD
sFileName = sName; tK3$,9+
this.nSplitter = nSpiltter; MSCH6R"5
\l/(L5gY
jwI2T$
} Q`k;E}x_-
&{Z+p(3Gj
aT,WXW*
public String getSSiteURL() 2XR!2_)O5
{ 7J);{ &x9h
return sSiteURL; bW`nLiw}%
} -HF?1c
%e:+@%]
EID-ROMO
public void setSSiteURL(String value) >g$iO`2
{ 1)~|{X+~
sSiteURL = value; OC&BJNOi
} EB3/o7)L
f&vMv.
jRsl/dmy
public String getSFilePath() Tb]7# v
{ z};|.N}
return sFilePath; ja9u?UbW
} - |peD L
v.RA{a 9
-|V#U`mwF
public void setSFilePath(String value) }1 O"?6
{ _gMr]%Q
sFilePath = value; PJK:LZw
} KH2]:&6:Q
LH54J;7Y
`oMZ9Gq2E
public String getSFileName() QvbH " 7
{ "}X+vd``
return sFileName; /4+L2O[
} "nz\YQdg
r5gqRh}+
F > rr.
public void setSFileName(String value) ~7b#BXzP
{ .5\@G b.8
sFileName = value; X+Sqw5rH
} >,,`7%Rv
Ar)EbGId
d./R;Z- I{
public int getNSplitter() @;O"-7Kk
{ ?GX@&_
return nSplitter; b}(c'W*z%
} s17)zi,?4
"`;-5dg
LGc8w>qE
public void setNSplitter(int nCount) l$5nv5r
{ (&.T
nSplitter = nCount; iY>P7Uvvz
} ViW2q"4=
} ]U#of O
.-YE(}^
@KM?agtlbl
/* f I%8@ :
**Utility.java B*:I-5
*/ 0:Bpvl5
package NetFox; %<^^ Mw
R?1Z[N
v{$?Ow T/u
public class Utility { ^Zvb3RJg
a=W%x{
)&E]
public Utility() 3*Q=)}
{ -"zW"v)\
;'Hu75ymo
8GBKFNR8
} E q4tcZ
v2tVq_\AMx
//线程睡眠 8d$|JN;)
public static void sleep(int nSecond) a;bmlV04
{ 4Q#{,y944
try{ yR~$i3Z*
Thread.sleep(nSecond); J<L\IP?%
} Y*#xo7#B
catch(Exception e) _#Hd2h
{ >NPK;Vu
e.printStackTrace (); n><ad*|MX
} k5>UAea_
} +8xT}mX
48z%dBmTT*
//日志 '__>M>[
public static void log(String sMsg) \5tG>>c i
{ oAifM1*0
System.err.println(sMsg); HY_>sD
} \s[L=^!
Syseiw
l1kHFeq
public static void log(int sMsg) Lios1|5
{ ..Dm@m}
System.err.println(sMsg); 8VG}-
} 8D>5(Dg-
} ,~,q0PA7J
!\|
T-yEn&r4)
/* WI&A+1CK-5
**TestMethod.java (gYW iz
*/ PZru:.Mh
package NetFox; ogSDV
=p5]r:9W
_"x%s
public class TestMethod { 1.u^shc&|
UUDbOxD^w
#qk=R7"Q
public TestMethod() MB:[: nX
{ ///xx/weblogic60b2_win.exe \^0>h`[
try{ (xvg.Nby
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q_p&~PNy5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iz;5:
SiteFileFetch fileFetch = new SiteFileFetch(bean); nCwA8AG
fileFetch.start(); =c 9nC;C
} vn*K\,
catch(Exception e){e.printStackTrace ();} ELV~ ayp5
wZ0bD&B
YJ6:O{AL1
} p&$PsgR
|Isn<|_
>`3F`@1L0
public static void main(String[] args) PSv 5tQhm
{ 8&HBR #
new TestMethod(); ;F- mt(Y
} iVnMn1h
} lO|LvJyx
点击下载更多相关资料