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)); "ZHW2l Mf
} |}23>l7
for(int i=0;i<nEndPos.length-1;i++) `(T,+T4C5k
{ d#6`&MR
nEndPos = nStartPos[i+1]; a5 *2h{i
} t c[n&X
nEndPos[nEndPos.length-1] = nFileLength; c?P?yIz6p
} )64@2~4y
} BeCWa>54i
.id)VF-l
NxSu3e~PS
//启动子线程 +U_=*"@|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *+'x~a
for(int i=0;i<nStartPos.length;i++) Ny_lrfh)[
{ Z:ni$7<.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1[kMOp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nYWvTvZ
nStartPos,nEndPos,i); Z -,J)gW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KiRUvWqa
fileSplitterFetch.start(); ]'5;|xc9$/
} _C.BFE_p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Y<|F!0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FSUttg"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qs|mj}?
nEndPos = " + nFileLength); .7zK@6i
// fileSplitterFetch[nPos.length-1].start(); |M8WyW
A"`foI$0
%cCs?ic
//等待子线程结束 "8'@3$>R=
//int count = 0; 3VuW#m#j
//是否结束while循环 np%\&CVhN
boolean breakWhile = false; y+!+ D[x
JBZUv
*o-.6OxZ$
while(!bStop) gWrgnlq
{ RZ6xdq}>
write_nPos(); 6Ztq
Utility.sleep(500); )Y]{HQd
breakWhile = true; !(qsD+
ub7zA!%
Q s.pGi0W
for(int i=0;i<nStartPos.length;i++) [(o7$i29|%
{ zR `EU,
if(!fileSplitterFetch.bDownOver) ~)qtply
{ qud\K+
breakWhile = false; PN0VQ/..
break; 1J6,]M
} .P.z B}0=
} tyfTU5"x
if(breakWhile) ygeDcnvR]
break; U`,0]"Qk
\(VTt|}By$
I6j$X6u
//count++; ,QC{3i~
//if(count>4) ^F2b hXE
// siteStop(); 3k|oK'l
} I<Ksi~*i
:gerQz4R8
o[v\|Q`d
System.err.println("文件下载结束！"); Z-8Yd6 4
} ?9! Z<H
catch(Exception e){e.printStackTrace ();} IGS1|
} rm4.aO~-F
wUiys/OVM
3l[McZ
//获得文件长度 Au{<hQ=
public long getFileSize() ^M%uV
{ %@;6^=
int nFileLength = -1; 0`)iIz
try{ @S|jC2^+h
URL url = new URL(siteInfoBean.getSSiteURL()); I#m-g-J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y7#-Fra0W
httpConnection.setRequestProperty("User-Agent","NetFox"); U7doU'V/
i:rFQ8I
90|7ArM_[
int responseCode=httpConnection.getResponseCode(); 6lkl7zm
if(responseCode>=400) !_+8A/
{ 8~9030>Q
processErrorCode(responseCode); BYTnrPA&Z;
return -2; //-2 represent access is error t|9 GS|
} %7#-%{
CNQC^d\ h
TT50(_8
String sHeader; XW -2~?$
X/z6"*(|/
zUkN 0
for(int i=1;;i++) JoRT&rkd
{ bV edFm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?pYKZg/c
//Utility.log(in.readLine()); U7!.,kR-
sHeader=httpConnection.getHeaderFieldKey(i); !O.[PH(,*
if(sHeader!=null) )x}l3\s
{ *<E]E?
if(sHeader.equals("Content-Length")) hX`hs-*qM
{ o;W`4S^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Y|~2Ls8tu
break; 'eo KZX+
} 4(Ov1a>
} .!1S[
else 5k6mmiaKk
break; gXonF'
} R)F;py8)I
} #VB')^d<U
catch(IOException e){e.printStackTrace ();} AK= h[2(
catch(Exception e){e.printStackTrace ();} [,K.*ZQi
CT KG9 T
0{[m%eSK'
Utility.log(nFileLength); %1.]c6U
JYrY[',u
[q_`X~3
return nFileLength; fV v.@HL{
} )LJnLo+
hq:&wN7Q
s@z}YH
//保存下载信息（文件指针位置） ~7$&WzD
private void write_nPos() Nc:({@I
{ ({-GOw46
try{ ! iptT(2
output = new DataOutputStream(new FileOutputStream(tmpFile)); %V1Z~HC
output.writeInt(nStartPos.length); yz-,)GB6
for(int i=0;i<nStartPos.length;i++) b B x?
{ :Xn7Ha[f
// output.writeLong(nPos); !ALKSiSl
output.writeLong(fileSplitterFetch.nStartPos); Nru7(ag1~
output.writeLong(fileSplitterFetch.nEndPos); qw7@(R'"
} DUL4noq{
output.close(); f'<Q.Vh<
} Mmo6MZ^
catch(IOException e){e.printStackTrace ();} Q\GDrdA
catch(Exception e){e.printStackTrace ();} yfjK2
} &K43x&mFF
y.=/J8->
]c<qM_HWg
//读取保存的下载信息（文件指针位置） `%E8-]{uS
private void read_nPos() X=6y_^
{ -DN8Yb
try{ i]=&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KjFK/Og.
int nCount = input.readInt(); Ti2Ls5H}
nStartPos = new long[nCount]; `}m Q
nEndPos = new long[nCount]; JXixYwm
for(int i=0;i<nStartPos.length;i++) ~`GhS<D
{ ik"sq}u_]E
nStartPos = input.readLong(); l"q1?kaVg
nEndPos = input.readLong(); /erN;Oo%<
} ed!:/+3e/
input.close(); zF@o2<cD@
} <W`#gn0b6
catch(IOException e){e.printStackTrace ();} ?9HhG?_x
catch(Exception e){e.printStackTrace ();} RP2_l$
} ari7iF~j
^A][)*SZ
QDTBWM%
private void processErrorCode(int nErrorCode) 8>7RxSF
{ kW`r=u
System.err.println("Error Code : " + nErrorCode); OFGsjYLw
} 5jgdbHog]
j}BHj.YuP
uk9g<<3T
//停止文件下载 Zes+/.sA}]
public void siteStop() xy8#2
{ ~ ^>417>
bStop = true; RQkyCAGx
for(int i=0;i<nStartPos.length;i++) $55U+)C<
fileSplitterFetch.splitterStop(); xrqv@/kJ
jSOS}!=
[3W*9j
} ;uqx@sx ;
} `:wvh(
//负责部分文件的抓取 sowd`I~
**FileSplitterFetch.java :^'O}2NP
*/ R#n%cXc|
package NetFox; R*zO dxY
!j1[$% =#
tp:\j@dB
import java.io.*; Um)>2|rp}
import java.net.*; ? b[n|^wS
C{Asp
sBK <zR
public class FileSplitterFetch extends Thread { 7 uMd ZpD
YB)3X[R+0
tu>{
String sURL; //File URL iB1i/l
long nStartPos; //File Snippet Start Position nRb^<cZf
long nEndPos; //File Snippet End Position c=[q(|+O!
int nThreadID; //Thread's ID jJ3zF3Id
boolean bDownOver = false; //Downing is over _Cy:]2o
boolean bStop = false; //Stop identical v)f7};"z
FileAccessI fileAccessI = null; //File Access interface .fzu"XAPu
cBYfXI0`
'r} zY-FM`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3L_I[T$s
{ TwvAj#j
this.sURL = sURL; LF?P> 1%-
this.nStartPos = nStart; ~:lKS;PRuK
this.nEndPos = nEnd; o5Y2vmz?9
nThreadID = id; F52B~@.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T;\^#1
} C}?0`!Cc%
~AG$5!
]h!`IX
public void run() [4+q+
{ 3+xy4G@L
while(nStartPos < nEndPos && !bStop) fd8!KO
{ VW@ x=m
S2C]?6cTq
g,]@4|
try{ "PH6e bm
URL url = new URL(sURL); 6QZ5|T ]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q (+ZwaV@
httpConnection.setRequestProperty("User-Agent","NetFox"); C+F*690h
String sProperty = "bytes="+nStartPos+"-"; !umEyd@ "
httpConnection.setRequestProperty("RANGE",sProperty); m"-[".-l-
Utility.log(sProperty); [9mL $;M W
@!Hr|k|
gVU1Y6.
InputStream input = httpConnection.getInputStream(); h:/1X' 3d
//logResponseHead(httpConnection); i2Jq|9,g
,>LRa
la$%H<,7
byte[] b = new byte[1024]; MS<SAD>w
int nRead; *Q}[ ]g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (LJ@SeM;
{ Gzt=u"FV
nStartPos += fileAccessI.write(b,0,nRead); ;\y;
//if(nThreadID == 1) w7-WUvxl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XD-^w_
} ] c}91
JmOW~W
5IqQ|/m<6
Utility.log("Thread " + nThreadID + " is over!"); fT Y/4(
bDownOver = true; !q4x~G0d
//nPos = fileAccessI.write (b,0,nRead); %do1i W
} h4fLl3%H
catch(Exception e){e.printStackTrace ();} pKJK9@Ad
} LD(C\
} DFe;4BdC
TSL9ax4j
7\/5r.
//打印回应的头信息 znZ7*S >6\
public void logResponseHead(HttpURLConnection con) ~# 7wdP
{ uCzii o`S
for(int i=1;;i++) Y:x/!-
{ V*65b(q)
String header=con.getHeaderFieldKey(i); zuL7%qyv
if(header!=null) 0y%L-:/c|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *]s&8/Gmb
Utility.log(header+" : "+con.getHeaderField(header)); ';RI7)<
else x:5dCI
break; )QY![&k}1z
} tSv0" L
} +=cam/A
_$/ +D:K
IS]{}Y\3H
public void splitterStop() gbOCR1PBg
{ \gccQig1CJ
bStop = true; mog9jw
} b>cafu
/N^~U&7
'pP-rdx
} w@]jpH;WX
eZF'Ck y
K]N~~*`%`
/* cfoYnM
**FileAccess.java B}*V%}:)
*//文件访问(定位，写) -G ?%QG`v
package NetFox; A['uD<4b
import java.io.*; y7zkAXhJ
IG.f=+<0
ValS8V*N1
public class FileAccessI implements Serializable{ pbB2wt
\~"#ld(x7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6w#nkF
RandomAccessFile oSavedFile; [}""@?
long nPos; ,5-Zb3\
?ow'^X-
PM~*|(fA
public FileAccessI() throws IOException aIGn9:\
{ _J"mR]I+
this("",0); &?a.mh/8[[
} QjukK6#W
mf*Nr0L;J
R40W'N1%q
public FileAccessI(String sName,long nPos) throws IOException wz@FrRP=
{ Y">4Qx4W
oSavedFile = new RandomAccessFile(sName,"rw"); Hbr^vYs5
this.nPos = nPos; ~8Sqa%F>
oSavedFile.seek(nPos); mC(u2
} hhq$g{+[
nN{dORJlx
1 Nk1MGV
public synchronized int write(byte[] b,int nStart,int nLen) ;?im(9h"v!
{ aR(E7mXQ
int n = -1; &d 3HB=x
try{ &|z544
oSavedFile.write(b,nStart,nLen); ag]*DsBt
n = nLen; \8_V(lU
} ABWb>EZ8
catch(IOException e) J'7 y
{ b:x7)$(
e.printStackTrace (); PHkDb/HIx|
} A#:8X1w
*98Ti|
{(HxG4~
return n; }=pOiILvD
} ]IXAucI]
FuMq|S
RdkU2Y}V
} F^TAd
-M`D>
jlRS:$|R0
/* 1E^{B8cm
**SiteInfoBean.java QJM(UfHUD
*/ =|#w.(3y
package NetFox; M5rwoyn
8DL hk
:xN8R^(
public class SiteInfoBean { u S(@?m$
;x RjQR
._K$0U!
private String sSiteURL; //Site's URL 6 <r2*`
private String sFilePath; //Saved File's Path X o_] v
private String sFileName; //Saved File's Name 67ZYtA|t
private int nSplitter; //Count of Splited Downloading File <!hpfTz*
Ix4jof6(
7n<#y;wo
public SiteInfoBean() $OT}`Te~
{//nSplitter的缺省值为5 q1<Fg.-r
//default value of nSplitter is 5 FB.!`%{
this("","","",5); q'fPNQg
} $KH@,;Xz
^VC7C~NZ!M
8t--#sDy{0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [ArO$X3\
{ A@\qoS[
sSiteURL= sURL; VEr 6uvB
sFilePath = sPath; qU}lGf!dVn
sFileName = sName; #Ul4&QVeg
this.nSplitter = nSpiltter; {4o\S
HUD7{6}4
Sn+FV+D
} olHH9R9:
rSzQUn<
X!2.IsIS8
public String getSSiteURL() KuU3DTS85Z
{ QR|XV%$
return sSiteURL; 9PUa?Bc`=
} A-X
ef^Cc)S-Q
P}+2>EU
public void setSSiteURL(String value) -??!@R7V
{ Z={D0`
sSiteURL = value; @*bvMEE
} d?Ia#K93G
0,;E.Py?.
g?w2J6Z.`J
public String getSFilePath() e~tr^$/(
{ rsd2v9
return sFilePath; }g%KvYB_
} kQqBHA
4!NfQk>X
bnAT,v{
public void setSFilePath(String value) Jslk
{ j` [#Ij
sFilePath = value; deR$
} "$`wk
Y\+(rC27
^zBjG/'7
public String getSFileName() MLkL.1eGSb
{ >cGh|_9
return sFileName; J-@o@!o
} ?/o2#iJx
{m?K2]](
K> c8r8!
public void setSFileName(String value) Z/XM`Cy
{ (#fm (@T
sFileName = value; r78u=r
} }:,o Y<
"R@$Wu53|
>reaIBT
public int getNSplitter() BFzcoBu-
{ $[HcHnf
return nSplitter; p?J~'
} t(Q&H!~e
Verbmeg&n
GnSgO-$"
public void setNSplitter(int nCount) { r<(t#
{ W\ 1bE(AwZ
nSplitter = nCount; o<C]+Nt,@
} |_hioMVz
} ~ LJ>WA
!=~s/{$PE
.}L-c>o"o
/* &cv@Kihq(
**Utility.java 0U>t>&,"
*/ C8bGae(
package NetFox; Q1O_CC}
`:-@E2
3/A!_Uc(
public class Utility { Lo$Z>u4(c
3*X,{%
>|UrxJ7
public Utility() *zw R=
{ cJ7{4YK_#/
ain#_H
@);!x41f
} 73^T*
imJ[:E
//线程睡眠 v&[X&Hu[
public static void sleep(int nSecond) [9db=$v8$
{ gL[1wM%?
try{ XEvGhy#
Thread.sleep(nSecond); <WQ<<s@#pb
} avHD'zU}N
catch(Exception e) 2yEO=SN,(
{ Vid{6?7kh
e.printStackTrace (); tdw\Di#m
} Gh)sw72
} -H ac^4uF
U- *8%>Qp
//日志 xzMeKC`
public static void log(String sMsg) D^N#E>,
{ BST7y4R)BS
System.err.println(sMsg); Q}=W>|aE.
} lJGqR0:r+
:XPC0^4s
@aqd'O
public static void log(int sMsg) uK4'n+_>\
{ LEn=dU
System.err.println(sMsg); O$<%z[
} aUIc=Z
} #TW>'lF
<y\ Z#z
Y?&DEKFbD
/* +s/N@]5nW
**TestMethod.java (A]m=
*/ k+7M|t.?4
package NetFox; R$T[%AGZ.
Wd^F%)(
Bah.\ZsYQP
public class TestMethod { [d^:
[U3D`V$xD
-hU>1ux&V
public TestMethod() @o3R`ZgC]\
{ ///xx/weblogic60b2_win.exe c:@OX[##
try{ ]9KQP-p'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aCYm$6LmA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w ~L\Ebg
SiteFileFetch fileFetch = new SiteFileFetch(bean); JK:mQ_
fileFetch.start(); mNnw G);$
} \AtwO
catch(Exception e){e.printStackTrace ();} lEYT{
<<W.x)#:
MWn L#!
} mSk :7ozZ
v]`A_)[
\:_.N8"
public static void main(String[] args) Y#SmZ*zok
{ 'wB Huq
new TestMethod(); K9I,Q$&xX
} pw<q?q%
} [oU+b(
点击下载更多相关资料