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)); ~;HASHu
} Kh3i.gm7g
for(int i=0;i<nEndPos.length-1;i++) {Vu=qNx
{ /uWUQ#9
nEndPos = nStartPos[i+1]; U9]&KNx
} ]4t1dVD
nEndPos[nEndPos.length-1] = nFileLength; Xn"#Zy_
} @lzq`SzM
} 1jx?zvE,
OFohyy(
$~8gh>`]
//启动子线程 CZzt=9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yFAUD ro
for(int i=0;i<nStartPos.length;i++) w_U#z(W3l
{ W _[9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S8v,'Cc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^X#)'\T
nStartPos,nEndPos,i); Zdrniae ah
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e[fld,s
fileSplitterFetch.start(); i`i`Hu>
} htYfIy{5w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s3Bo'hGxG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "'DPb%o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CM~x1f*v
nEndPos = " + nFileLength); 6U).vg<
// fileSplitterFetch[nPos.length-1].start(); sB0]lj-[Un
iw.F8[})
k'X"jon
//等待子线程结束 <YCjo[(~
//int count = 0; p+Yy"wH:h{
//是否结束while循环 [?6+ r
boolean breakWhile = false; \V~B+e
~&,S xQT
oJVdFE
while(!bStop) <OiH%:G/1
{ &#C|
write_nPos(); ?z. Z_A&
Utility.sleep(500); ,wr5DQ
breakWhile = true; Eb,M+c?
b 2\J<Nw
.mnkV -m
for(int i=0;i<nStartPos.length;i++) W^W.* ?e`
{ YxnZ0MY
if(!fileSplitterFetch.bDownOver) u$qasII
{ 0 Swu]OE
breakWhile = false; >xRUw5jN
break; 7iy2V;}
} Us[F@
} _or_Vw!
if(breakWhile) g6gwNC:aF
break; {#t7lV'4
t.!?"kP"c
c*w0Jz>@.7
//count++; Nn0j}ZI)1
//if(count>4) }V/iU_)
// siteStop(); ~Y1nU-
} a/CY@V-
rZAP3)dA
9G1ZW=83
System.err.println("文件下载结束！"); P(\x. d:
} vqF=kB"P
catch(Exception e){e.printStackTrace ();} F.Bij8\
} }L`Z<h*H
&G-dxET]
$;";i:H`
//获得文件长度 O*F= xG
public long getFileSize() N+]HJ`K
{ 6 {`J I
int nFileLength = -1; [$]-W$j+
try{ A(XX2f!i
URL url = new URL(siteInfoBean.getSSiteURL()); }Oe4wEYN)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -g"Wi@Qr
httpConnection.setRequestProperty("User-Agent","NetFox"); >N0L
cI6Td*vM
?:5/4YC
int responseCode=httpConnection.getResponseCode(); (s+}l?
if(responseCode>=400) tI0D{Xrc
{ e ?Jgk$"
processErrorCode(responseCode); s=R^2;^
return -2; //-2 represent access is error OSJL,F,
} Cpn!}!Gnf
oB<!U%BN
qus%?B{b}
String sHeader; ubKp P%Z
i:&$I=
e=!sMWx6
for(int i=1;;i++) 6/0bis H
{ =FAIbM>u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +wEsfYW
//Utility.log(in.readLine()); Tj2pEOu
sHeader=httpConnection.getHeaderFieldKey(i); 6ZXRb
if(sHeader!=null) M"Y,kA|+
{ h5n@SE>G
if(sHeader.equals("Content-Length")) ;e2D}
{ .8|"@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^C2SLLgeJ
break; uesIkJ^Q[
} j3R}]F'C*
} f?QP(+M5.
else dA#'HMh@
break; Nc^:v/(P
} }+:X=@Z@
} 7Zft]C?|@
catch(IOException e){e.printStackTrace ();} @6y)wA9Yx
catch(Exception e){e.printStackTrace ();} e\ZV^h}TQ
gP!k[E,Q8
Gfepm$*%
Utility.log(nFileLength); "`KT7
VTO92Eo
nwi8>MG
return nFileLength; 0,cU^HMA
} B}I9+/|{
d(vt0
,W$&OD
//保存下载信息（文件指针位置） =+4om*
private void write_nPos() CE4Kc33OU|
{ 1_mqPMm
try{ 8%Ak
output = new DataOutputStream(new FileOutputStream(tmpFile)); )'/xNR
output.writeInt(nStartPos.length); h.xtkD)Y~
for(int i=0;i<nStartPos.length;i++) cf\GC2+"^$
{ -^>7\]
// output.writeLong(nPos); _!yUr5&,Br
output.writeLong(fileSplitterFetch.nStartPos); U_wIx
output.writeLong(fileSplitterFetch.nEndPos); rwpH9\GE
} :?gp}.
output.close(); t&o&gb
} aC3Qmo6?m
catch(IOException e){e.printStackTrace ();} P(p|NRD@1
catch(Exception e){e.printStackTrace ();} Nm#[A4
} \XbCJJP
}?6gj%$c
m-9ChF:U
//读取保存的下载信息（文件指针位置） m>DJ w7<
private void read_nPos() SS&G<3Ke
{ @f#6Nu
try{ k4JTc2b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fTGVG
int nCount = input.readInt(); .p78 \T
nStartPos = new long[nCount]; Hr(%y&0
nEndPos = new long[nCount]; Dyj>dh-
for(int i=0;i<nStartPos.length;i++) +@+*sVb
{ );xTl6Y9
nStartPos = input.readLong(); AZ. j>+0xx
nEndPos = input.readLong(); F{eI[A
} VP }To
input.close(); A ?[Wfq|
} [n$6T
catch(IOException e){e.printStackTrace ();} &3 x [0DV
catch(Exception e){e.printStackTrace ();} K*tomy
} xE6hE'rh.O
p%+'iDb
T?*f}J
private void processErrorCode(int nErrorCode) 5~RR _G
{ xQxq33\
System.err.println("Error Code : " + nErrorCode); mfk^t`w_
} 3oApazH*
V+$fh2t
._6Q "JAB
//停止文件下载 xH>j
public void siteStop() H6MG5f_
{ l-8rCaq&J
bStop = true; B#o6UO\
for(int i=0;i<nStartPos.length;i++) V17!~
fileSplitterFetch.splitterStop(); Eg_ram`\R
$v1_M1
(~?p`g+I.P
} ,b t j6hg
} rb]?"lizi
//负责部分文件的抓取 |}o3EX
**FileSplitterFetch.java x-~=@oiv
*/ Am"&ApK
package NetFox; 5wC,:c[H7
B|r'
-7VQ{nC
import java.io.*; 2CV?cm
import java.net.*; yg82a7D
^MvBW6#1
#l!nBY~
public class FileSplitterFetch extends Thread { HnKXO
QVkrhwp
e. R9:
String sURL; //File URL ggy9euWV
long nStartPos; //File Snippet Start Position CsN^u H
long nEndPos; //File Snippet End Position cT nC
int nThreadID; //Thread's ID V}Ce3wgvA
boolean bDownOver = false; //Downing is over FQ u c}A
boolean bStop = false; //Stop identical a:F\4x=
FileAccessI fileAccessI = null; //File Access interface !iW>xo
8Y/1+-
%m-U:H.Vp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8;x0U`}Ez(
{ T_fM\jdI
this.sURL = sURL; -]Q\G
this.nStartPos = nStart; YRU95K[
this.nEndPos = nEnd; H'&[kgnQ@
nThreadID = id; /25Ay
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s133N?
} yV*4|EkvW
$t0JfDd6Ky
]#vi/6\J
public void run() Qw<&N$
{ sGc.;":
while(nStartPos < nEndPos && !bStop) Cl!9/l?z
{ 9^@)R ED
0!M'z
\t)`Cp6,[b
try{ wYQEm
URL url = new URL(sURL); R$;TX^r'o&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )T^xDx
httpConnection.setRequestProperty("User-Agent","NetFox"); i:1 @ vo
String sProperty = "bytes="+nStartPos+"-"; zpZfsn!
httpConnection.setRequestProperty("RANGE",sProperty); \}_,g
Utility.log(sProperty); J|`.d46
w8a49Fv
\J;_%-Z
InputStream input = httpConnection.getInputStream(); I:("f+ H
//logResponseHead(httpConnection); DKF '*
5<YL^m{/L
tTWEhHQ`
byte[] b = new byte[1024]; 'UM *7
int nRead; d{Owz&PL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A#Y:VavQ?
{ .h(iyCxP
nStartPos += fileAccessI.write(b,0,nRead); <LN7+7}
//if(nThreadID == 1) %*#+(A"V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `@#rAW D
} b7B|$T,
nlA:C>=
',/2J0_
Utility.log("Thread " + nThreadID + " is over!"); Y(R.<LtY
bDownOver = true; $=) Pky-~
//nPos = fileAccessI.write (b,0,nRead); {(I":rt#
} (%mV,2|:20
catch(Exception e){e.printStackTrace ();} Z58{YCY
} PbsxjP
} n]i#&[*A(
mi[8O$^iJ
!s:e
//打印回应的头信息 'xEK0~awD
public void logResponseHead(HttpURLConnection con) IhOAMH1
{ ?:G 3U\M
for(int i=1;;i++) buT6)~lw
{ _n_()at)
String header=con.getHeaderFieldKey(i); ;a| ~YM2I
if(header!=null) ck\W'Y*Q7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iu3L9UfL[
Utility.log(header+" : "+con.getHeaderField(header)); {8h[Bd
else GP^.h kVs
break; 'by+hXk
} 4u+0 )<
} uqLP$At
dCeLW
Nd&UWk^
public void splitterStop() XK})?LTD
{ Keem\/
bStop = true; ZJ.an%4
} SMzq,?-`
m xqY
<'N:K@Cs
} </u=<^ire
*QV"o{V
ambr}+}
/* z+-o}i
**FileAccess.java 1GK>&;
*//文件访问(定位，写) e[s}tjx
package NetFox; 9bspf {
import java.io.*; : ]+6l
} `5k^J$x
Wky9wr:g
public class FileAccessI implements Serializable{ ^39lUKL
: ^("L,AF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M:b#">M
RandomAccessFile oSavedFile; =4l @A>
long nPos; )BvMFwQG
Hf\sF(, (
kguZAO6
public FileAccessI() throws IOException +@~WKa
{ aU^6FI
this("",0); b?c/J{me
} U7?v4O]D[
0Qq<h;8xEc
=*"8N-FU
public FileAccessI(String sName,long nPos) throws IOException ]Yw$A
{ ts9wSx~[+
oSavedFile = new RandomAccessFile(sName,"rw"); a[ayr$Hk?
this.nPos = nPos; ^ nI2<P
oSavedFile.seek(nPos); "r*`*1
} QXN_ ?E,g/
*BdH &U
y.c6r> }
public synchronized int write(byte[] b,int nStart,int nLen) n:P:im?,y*
{ h<TZJCt
int n = -1; QS5t~rb
try{ E6ZkO/
oSavedFile.write(b,nStart,nLen); \2e^x
n = nLen; `$S&:Q,
} p@nj6N.--
catch(IOException e) {:|3V 7X
{ f:ObI
e.printStackTrace (); /s} "0/Y\
} {(!JYz~P
1l"2 ~k
rM"27ud[`_
return n; d?T!)w
} b5LToy:
q\]X1N
}cr'o"4
} YrB-n
^9:`D@Z+
V5z2.} 'o-
/* 9$HBKcO
**SiteInfoBean.java )c{>@WM~
*/ 3ie k>'T
package NetFox; RYjK4xT?Y/
}b&lHr'Uw
?VmgM"'md
public class SiteInfoBean { oV0T
9K/EteS
2Y23!hw
private String sSiteURL; //Site's URL |w}j!}u
private String sFilePath; //Saved File's Path dN)8r
private String sFileName; //Saved File's Name T7.Iqw3p
private int nSplitter; //Count of Splited Downloading File @$ Zh^+x!
Z17b=xJw
BZ1wE1t
public SiteInfoBean() Y~85Z0l
{//nSplitter的缺省值为5 gS5MoW1
//default value of nSplitter is 5 Y=O+d\_W
this("","","",5); >&KH!:OX|
} 9<.O=-1~
[ gMn
e;"J,7@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E|"SMA,
{ KE~Q88s
sSiteURL= sURL; YHQ]]#'
sFilePath = sPath; 3HpqMz
sFileName = sName; M7cD!s@'I
this.nSplitter = nSpiltter; 8qg%>ZU4d
C$TU TS
ou<3}g
} XGR2L DR
s@@Km1w
A-T-4I
public String getSSiteURL() _&hM6N
{ mi7?t/D1Z
return sSiteURL; 2c 0;P #ol
} 5MaN {*)l
V;xPZ2C;
J W@6m
public void setSSiteURL(String value) Wvf>5g)?
{ gZ$ 8Y7
sSiteURL = value; ~3?-l/$
} EGUlLqP6e
{MUiK5:
e"%TU
public String getSFilePath() gHBvQ1g
{ 1fS&KO{a
return sFilePath; >] 'oN
} {x_.QWe5
0N$7(.
UpGDLbf^
public void setSFilePath(String value) 5MB`yRVv
{ I]v2-rB&-
sFilePath = value; P);s0Y|@H
} ?f"5yQ-B
TjTG+uQ
sip4,>,E
public String getSFileName() G|rE\h 2w
{ :@[\(:
return sFileName; E{u6<B*
} 0vm>*M*p
hLLSmW(
:S0!
public void setSFileName(String value) 5;/n`Bd
{ CW &z?Bra
sFileName = value; #y:D{%Wp
} g8##Be
51q|-d
u]IbTJ'
public int getNSplitter() kWXLncE
{ Kd5'2"DI
return nSplitter; wc;n= %
} qg oB}n%
z3+@[I$
.d1ff];
public void setNSplitter(int nCount) 9;e!r DW,#
{ .C% 28fH
nSplitter = nCount; )y,^M3$?C
} 5)!g.8-!
} :snO*Zg
$ZBYOA
yDafNH
/* A9MM^jV8
**Utility.java <giBL L!
*/ QM0B6F
package NetFox; t>\sP
a_>|Ny6{
=b%}x >>
public class Utility { \;X7DK2
+lx&$mr?
2|je{
public Utility() A`Z/B[)
{ M/?,Qii
c C3>Ff'
l*1|B3#m!
} e3p|g]
|"gL{De
//线程睡眠 y@3p5o9lv-
public static void sleep(int nSecond) t%lat./yT
{ rm[C{Pn
try{ >$4#G)s
Thread.sleep(nSecond); $d?W1D<A
} HT;^u"a~
catch(Exception e) ]3_b3@k
{ ,;`f* #
e.printStackTrace (); Tlw'05\{J
} 7Z6=e6/\
} WoEK #,I;
nq M7Is
//日志 p~$cwbQ!
public static void log(String sMsg) O(T5
{ $H)^o!
System.err.println(sMsg); 4@PA+(kvS
} Xqf,_I=V
|THpkfW
:o'x?]
public static void log(int sMsg) o!M8V ^vW
{ 4Z)s8sDKW
System.err.println(sMsg); ~bLx2=-"
} \R#SoOd
} )'djqpM.
%k!CjW3
a`!Jq'
/* "n%s>@$
**TestMethod.java Oidf\%!mvR
*/ Qm%PpQ^Lz3
package NetFox; |bY@HpMp
1$>+rW{a
|[*Bn3E:
public class TestMethod { /{^k8 Q
@Vm*b@
%O"8|ZG9{
public TestMethod() ]@{Lx>Oh"
{ ///xx/weblogic60b2_win.exe K zWo}tT
try{ |toP86
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 40t xZFQ0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JVc{vSa!rm
SiteFileFetch fileFetch = new SiteFileFetch(bean); _ \D%
fileFetch.start(); 2cMCZuO
} 4zoQe>v~
catch(Exception e){e.printStackTrace ();} RzEzNV
+,76|oMsQ%
=Hi@q "
} s2<!Zb4
/(dP)ysc
2JfSi2T
public static void main(String[] args) ./YR8#,
{ KgL!~J
new TestMethod(); b($hp%+yJ
} da$FY7
} xRh 22z
点击下载更多相关资料