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)); EG1SIEo
} g^]Q*EBa
for(int i=0;i<nEndPos.length-1;i++) UIu'x_qc
{ {`3;Pd`
nEndPos = nStartPos[i+1]; De^is^{
} #~#_)\l'F
nEndPos[nEndPos.length-1] = nFileLength; nxH$$}9
} r^ "mPgY
} yDyq. -Q
t^7R6y
yk#:.5H
//启动子线程 @E==~ b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ib#x~Db
for(int i=0;i<nStartPos.length;i++) @L~y%#
{ '17=1\Ss6;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~pF'Qw"z|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o+tY[UX
nStartPos,nEndPos,i); &bL1G(}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V)0bLR
fileSplitterFetch.start(); HSUr
} qGh rJ6R!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2R5]UR S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v)pdm\P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ae^xuM?7
nEndPos = " + nFileLength); c{852R
// fileSplitterFetch[nPos.length-1].start(); Y8AU<M
%V+,#
Us%VBq
//等待子线程结束 -(59F
//int count = 0; j"NqNv
//是否结束while循环 fx}R7GN2
boolean breakWhile = false; =_wgKXBFa
ioviJ7N% O
A2vOI8
while(!bStop) d>aZpJ[.
{ v\HGL56T
write_nPos(); a1}W2;W0]g
Utility.sleep(500); Z>D7C?v:(
breakWhile = true; bh_ALu^CSX
.Ftml'!
A] F K\
for(int i=0;i<nStartPos.length;i++) 2dq{n.cgs
{ LEhi/>T
if(!fileSplitterFetch.bDownOver) (Q'XjN\#
{ ;wN.RPE_^
breakWhile = false; R]r~TJ o
break; }U(^QB
} ]>AW
} r`&ofk1K
if(breakWhile) "7aFVf
break; 9u)h$VC
Og&2,`Jb
$]T7Iwk
//count++; F1+2V"~
//if(count>4) bk7miRIB
// siteStop(); U .rH,`
} bX9}G#+U
KcrF=cA
o/[NUQSI
System.err.println("文件下载结束！"); *U]f6Q<X
} 'Wi*[
catch(Exception e){e.printStackTrace ();} xp39TiXJ*
} 0qTa@y
3oIoQj+D
B02~/9*Y"
//获得文件长度 "90}H0(+
public long getFileSize() :N[2*.c[
{ .O,gl$y}
int nFileLength = -1; hrW.TwK
try{ 0}b8S48|?
URL url = new URL(siteInfoBean.getSSiteURL()); V}JW@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T|}HK]QOX
httpConnection.setRequestProperty("User-Agent","NetFox"); .6tz ^4
/!E /9[V
Uvuvr_IP
int responseCode=httpConnection.getResponseCode(); S\f^y8*<
if(responseCode>=400) 7<KRB\)b&
{ -kJF@w6u
processErrorCode(responseCode); FIS-xpv$
return -2; //-2 represent access is error ~pw_*AN
} d_yqmx?w
bcZHFX
`Yut1N
String sHeader; p"X\]g^jA>
VJNPs6
L,l+1`Jz
for(int i=1;;i++) Gm|QOuw
{ Jsw<,uTD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A1Zu^_y'
//Utility.log(in.readLine()); ZWr\v!4
sHeader=httpConnection.getHeaderFieldKey(i); \"lzmxe0p
if(sHeader!=null) Zc"]Cv(
{ 7_{x '#7
if(sHeader.equals("Content-Length")) +FJ o!~1
{ a;lCr|*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `=\G>#p<T
break; ;j(xrPNb
} cis~]x%
} 0 @,@
else 10DS
break; %d=-<EQ|&
} `P GWu1/
} s_kI\w4(x1
catch(IOException e){e.printStackTrace ();} M'g4alS
catch(Exception e){e.printStackTrace ();} (0k0gq;
bc 0|tJc
P@Qo2zTh%
Utility.log(nFileLength); F-ZD6l9O
.f6_[cS;g
SGbo|Xe7:
return nFileLength; 6\]-J*e>
} Pjx9@i
Gis'IX(
;ndg,05_
//保存下载信息（文件指针位置） 6?t5g4q*nn
private void write_nPos() GY4yZa
{ e;gf??8}
try{ P(Lwpa,S
output = new DataOutputStream(new FileOutputStream(tmpFile)); BY 1~\M
output.writeInt(nStartPos.length); S#""((U$
for(int i=0;i<nStartPos.length;i++) CsE|pXVG
{ hMDyE.X-
// output.writeLong(nPos); D_8hn3FH
output.writeLong(fileSplitterFetch.nStartPos); Jv7M[SJ#x
output.writeLong(fileSplitterFetch.nEndPos); 9np<r82
} W]R5\G*
output.close(); gG$o8c-
} R vY`9D
catch(IOException e){e.printStackTrace ();} /wK7l-S
catch(Exception e){e.printStackTrace ();} hqE#BnQxP,
} +wio:==
?Z.YJXoKZ
JlH|=nIaj6
//读取保存的下载信息（文件指针位置） }KOu
private void read_nPos() WTd}) s
{ A8A+ImwO"
try{ uIba{9tM"P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RJ-CWt [LG
int nCount = input.readInt(); w}E?FEe.
nStartPos = new long[nCount]; 1]kk
nEndPos = new long[nCount]; vi=yR
for(int i=0;i<nStartPos.length;i++) 1k hwwoo
{ _\1(7?0D
nStartPos = input.readLong(); +6>Pp[%
nEndPos = input.readLong(); 1E-$f
} `SU;TN0
input.close(); AHLDURv
} !YoKKG~_0
catch(IOException e){e.printStackTrace ();} 7eq;dNB@gq
catch(Exception e){e.printStackTrace ();} . XY'l
} $)uQ%/DH>
C=Zuy^
Nd0Wt4=
private void processErrorCode(int nErrorCode) weDv[b5i
{ }\irr9,
System.err.println("Error Code : " + nErrorCode); 5<S1,u5
} 6jnRC*!?
(z.Vwl5
G9gvOEI/
//停止文件下载 \2LCpN
public void siteStop() c.XLEjV|
{ @e slF
bStop = true; I4)vJ0
for(int i=0;i<nStartPos.length;i++) ]~oM'?&!
fileSplitterFetch.splitterStop(); Rp|:$5&nE
"C.$qk]
?@u &3/&
} !]`]67lC
} Zdak))7
//负责部分文件的抓取 d#W[<,
**FileSplitterFetch.java D~{)\;w^!
*/ %:/;R_
package NetFox; !l&lb]Vcz
&fTCY-W[
l%)XPb2$J
import java.io.*; FX'W%_f,
import java.net.*; ~C[,P\,
m1cyCD
nQgn^z#
public class FileSplitterFetch extends Thread { D +oo5
v:+se6HY?p
6$zUFIk
String sURL; //File URL <&NR3^Eq
long nStartPos; //File Snippet Start Position S !e0:
long nEndPos; //File Snippet End Position qlzL<
int nThreadID; //Thread's ID K[9<a>D`
boolean bDownOver = false; //Downing is over {<i!Pm
boolean bStop = false; //Stop identical }Jc^p
FileAccessI fileAccessI = null; //File Access interface *7Mrng
II2oV}7?
;S%wPXj&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;uJVY)7a
{ \GkcK$Y
this.sURL = sURL; 6ZM<M7(V
this.nStartPos = nStart; @3G3l|~>
this.nEndPos = nEnd; K>q,?x b
nThreadID = id; ~!uK;hI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fpqKa r
} 6m{3GKaW~
63~i6
\ pq]q
public void run() \gzNMI*
{ g_q{3PW.
while(nStartPos < nEndPos && !bStop) eD/?$@y
{ EEaFi8
|GsLcUv6
}{ P}P}
try{ Rw7Q[I5z%
URL url = new URL(sURL); +uH1rF_&@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H<>x_}&
httpConnection.setRequestProperty("User-Agent","NetFox"); ZE1#{u~[y
String sProperty = "bytes="+nStartPos+"-"; 2{%BQq>C
httpConnection.setRequestProperty("RANGE",sProperty); W[vak F
Utility.log(sProperty); ~vt8|OOo0
f&,.h"bS
[m4<j
InputStream input = httpConnection.getInputStream(); ':fVb3A[*d
//logResponseHead(httpConnection); 4f>Vg$4
qzH97<M}T
> vahj,CZZ
byte[] b = new byte[1024]; 'E@D
int nRead; AvwX 2?tc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eC3ZK"oJ
{ }b{N[
nStartPos += fileAccessI.write(b,0,nRead); 1\3n
//if(nThreadID == 1) 1,/oS&?E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )i?wBxq'MA
} #A|MNJ%m
5zUD W?
w ggl,+7
Utility.log("Thread " + nThreadID + " is over!"); 'Kq%tM26!
bDownOver = true; &^Xm4r%u_
//nPos = fileAccessI.write (b,0,nRead); 4}0s^>R
} a]Lr<i8#%
catch(Exception e){e.printStackTrace ();} YlYTH_L>E
} )cvC9gt
} +Oxl1fDf
P3:hGmk8|j
*v&g>Ni
//打印回应的头信息 Z)ObFJMG5
public void logResponseHead(HttpURLConnection con) N#UyAm<9
{ D,R/abYZH
for(int i=1;;i++) ){,8}(|
{ 0>AA-~=-
String header=con.getHeaderFieldKey(i); ed617J
if(header!=null) e06r5%|.%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VJPt/Dy{
Utility.log(header+" : "+con.getHeaderField(header)); Vdjca:`
else f6z[k_lLN
break; sqkPC_;A
} jfI|( P
} toP7b
zIlQqyOQ8
m7d? SU
public void splitterStop() (l$bA_F\
{ X09&S4
bStop = true; x&7!m
} ]@<O!fS
1_F2{n:yp
x&kF;UC
} Wx^L~[l
BK-{z).)
C^uXJ~8
/* pE`BB{[@
**FileAccess.java `M|fwlAJQ
*//文件访问(定位，写) R@ihN?k
package NetFox; mH;\z;lyK
import java.io.*; `i<U;?=0'
<Nkj)`%5iK
-`A6K!W&~p
public class FileAccessI implements Serializable{ %SIbpk%
_TkiI.'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZX'/[wAN)
RandomAccessFile oSavedFile; 1YQ|KJ*K
long nPos; >8QLo8)3C
t.3b\RV[
k|&@xEbS
public FileAccessI() throws IOException MvQ0"-ZQ
{ tLLP2^_&
this("",0); pWeKN`
} l].dOso$`
O,hT< s "
VBy=X\w]
public FileAccessI(String sName,long nPos) throws IOException V:yia^1
{ rry 33
oSavedFile = new RandomAccessFile(sName,"rw"); `2}Mz9mk
this.nPos = nPos; Z}WMpp^r
oSavedFile.seek(nPos); l+RBe<Mq
} (rvK@
+1_NB;,e
"*<9)vQ6|
public synchronized int write(byte[] b,int nStart,int nLen) s<aJ pi{n4
{ j^>J*gLM}W
int n = -1; XB^o>/|@S
try{ ;QS-a
oSavedFile.write(b,nStart,nLen); 4y:yFTp
n = nLen; l(*`,-pv:
} gP?pfFhG
catch(IOException e) N<9CV!_
{ R9^Vk*`gFU
e.printStackTrace (); RYy_Ppn96f
} +AO(e
A-qdTJP
pm@Mlwg`1
return n; KP%A0
} ~CQsv`
/n&w|b%
G D$o|l]\
} up#W"`"
4uwI=UUB
Jzo|$W
/* >2tYw,m
**SiteInfoBean.java !T!U@e=u
*/ xhWWl(r`5
package NetFox; u%}zLwMH
JN,4#,
^cn%]X#.
public class SiteInfoBean { Il`35~a
=# <!s!
JgEPzHgx
private String sSiteURL; //Site's URL Se{}OG)
private String sFilePath; //Saved File's Path /0A9d-Qd<
private String sFileName; //Saved File's Name ]MKW5Kq
private int nSplitter; //Count of Splited Downloading File XShi[7
-c{O!z6sX
p D-k<8|
public SiteInfoBean() \QGh@AQp"
{//nSplitter的缺省值为5 Op0n.\>
//default value of nSplitter is 5 p(=}Qqdr8
this("","","",5); Cjc>0)f&.
} +`}QIp0
ibAZ=RD
*eK\W00
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &e0BL z
{ m&a.i B
sSiteURL= sURL; W US[hx,
sFilePath = sPath; H|JPqBNRh
sFileName = sName; TF R8
this.nSplitter = nSpiltter; G)t_;iNL|
o<cg9
1DLAfsLlj
} 6V-u<FJ
mSdByT+dG
:#7"SEud}
public String getSSiteURL() 6?i]oy^X]p
{ <n? cRk'.
return sSiteURL; 42]hX9E
} T+1:[bqK
G9v'a&
:{BD/6
public void setSSiteURL(String value) `1 A,sXfa
{ >}?jOB
sSiteURL = value; A{NKHn>%`
} 4&N#d;ErC
Pw+PBIGn4
JbX"K< nQ
public String getSFilePath() oN({X/P2j
{ sE:~+C6o:
return sFilePath; H{M7_1T
} G5A:C(r
EdcbWf7
QiKci%=SX
public void setSFilePath(String value) J'}G~rB<<
{ ~?#>QN\\c
sFilePath = value; *uW l 804
} 7qsu0 .[d
e%[0 NVo
!$n@-
public String getSFileName() hQ7-m.UZw
{ 4*Uzomb?q
return sFileName; fab.%$
} w}|XSJ!
HKp|I%b]J
UlP2VKM1&
public void setSFileName(String value) S3oyx#R('O
{ aQ.QkMZ
sFileName = value; G.")Bg
} |#(KP
A:b(@'h
w :nYsuF
public int getNSplitter() 5}C.^J`
{ 'Dn\.x^]1
return nSplitter; [J!jp&o
} ~F"<Nq
a_Sp}s<J
b!p]\B!
public void setNSplitter(int nCount) NMs8^O|0
{ r{cmw`WA/P
nSplitter = nCount; DplS\}='s
} [x%[N)U3
} I4XnJ[N%
\qf0=CPw8
kz_gR;"(Z
/* z( \4{Y
**Utility.java M}fk[Yr>
*/ $-=xG&fSz
package NetFox; B%7Az!GX
/ f5q9sp8
22OfbwCb
public class Utility { 9epMw-)k
cslZ;
y#T.w0*
public Utility() r1axC%
{ ^r=Wj@`
s5/u>d
NiH =T
} ~] &yHzp2
`- HI)-A97
//线程睡眠 TTa$wiW7'
public static void sleep(int nSecond) 8TBv~Qu
{ FMOO
try{ $-)T
Thread.sleep(nSecond); @ D,]v:
} f@@7?5fW
catch(Exception e) l"zA~W/
{ ;~-ZN?8
e.printStackTrace (); TMsc5E
} jj&mRF0gCb
} I A%ZCdA;
3qW](
//日志 B[.$<$}G
public static void log(String sMsg) skm~~JM^
{ 38 ]}+Bb
System.err.println(sMsg); ;Rlf[](iL
} Z;O!KsJ
t[r6jo7
Sa[?B
public static void log(int sMsg) =X1oB,W{
{ !,+<?o y
System.err.println(sMsg); `w&?SXFO8
} z:a7)z
} ]]o?!NX
Kf-XL),3l
o|$r;<o3R
/* RNF%i~nhO
**TestMethod.java &S=Qu?H
*/ 2`^6``
package NetFox; gR+P!Eow
Mkh/+f4
[_eT{v2B4
public class TestMethod { ppo.#p0w
{,!!jeOO
-{}(U
public TestMethod() ]=o1to-
{ ///xx/weblogic60b2_win.exe L+mE&
try{ 6FYL},.R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &OlX CxH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =xQPg0g
SiteFileFetch fileFetch = new SiteFileFetch(bean); v%r/PHw
fileFetch.start(); O>N/6Z
} {)iiu
catch(Exception e){e.printStackTrace ();} 3:O|p[2)L
aGOS9
PR/>E60H
} '>ASr]Q
%+nM4)h
M]|]b-#
public static void main(String[] args) Y<IuwS
{ Ee_?aG e&
new TestMethod(); /6rQ.+|).
} h<V,0sZ&:
} o|u4C{j
点击下载更多相关资料