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)); _bMs~%?~/
} 'Y"q=@Ei9
for(int i=0;i<nEndPos.length-1;i++) vkR"A\:
{ i!,>3
nEndPos = nStartPos[i+1]; ![Jxh,f
} *2@q=R-1
nEndPos[nEndPos.length-1] = nFileLength; , H[o.r=
} T_gW't>
} 9Xm"kVqd/
VNytK_F0P
}l[t0C t
//启动子线程 V@Po}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N$=<6eQm
for(int i=0;i<nStartPos.length;i++) d;CD~s
{ Z)?"pBv'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AMO{?:8Y;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TUk1h\.q
nStartPos,nEndPos,i); zSq+#O1#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j f^fj-
fileSplitterFetch.start(); !Sw7!h.ut
} f'%}{l: ss
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \j K?R 6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cCj}{=U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8H{@0_M
nEndPos = " + nFileLength); *YDx6\><
// fileSplitterFetch[nPos.length-1].start(); }D|"$*
u(REEc~nj
^rxXAc[
//等待子线程结束 LL,~&5{
//int count = 0; v=X\@27= ?
//是否结束while循环 mY%PG
boolean breakWhile = false; a!>AhOk.
8\ :T*u3
;#j/F]xG
while(!bStop) Y}Qu-fm
{ XVI+Y
write_nPos(); XE>XzsnC
Utility.sleep(500); p6ZKyi
breakWhile = true; .Wa6?r<g
h"<rW7z
r<bg->lX
for(int i=0;i<nStartPos.length;i++) i@g6%V=
{ sjzZl*GSy
if(!fileSplitterFetch.bDownOver) kU#$
{ L:%h]-
breakWhile = false; 0,VbB7 z
break; thq(tK7
} I/'jRM
} 5B@&]-'~
if(breakWhile) G-;pMFP(?
break; s=KA(4p
,Ma$:6`f
5SK.R;mn
//count++; -$mzzYH
//if(count>4) <GR]A|P
// siteStop(); jdoI)J@9H
} < Gu s9^_
\9 ^wM>U
UHxXa*HyI
System.err.println("文件下载结束！"); GadD*psD2
} oFY'Ek;d
catch(Exception e){e.printStackTrace ();} b9"Q.*c<Z^
} E7 7Au;TL
`VS/Xyp
*VL-b8'A<
//获得文件长度 TT29LC@
public long getFileSize() %3~jg
{ _\u'~wWl
int nFileLength = -1; :@n e29,}
try{ /)v X|qtIY
URL url = new URL(siteInfoBean.getSSiteURL()); -1U]@s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); okfhd{9
httpConnection.setRequestProperty("User-Agent","NetFox"); 2.2 s>?\
|qZ4h7wL
$@DXS~UQA
int responseCode=httpConnection.getResponseCode(); !$&K~>`
if(responseCode>=400) U?.VY@
{ n.Ekpq\
processErrorCode(responseCode); ,@GI3bl
return -2; //-2 represent access is error jagsV'o2
} =G*<WcR
m}8c.OJ>K`
! 5]/2
String sHeader; ]Wfnpqc^
hGzj}t W8d
0naegy?,
for(int i=1;;i++) l$z-'
{ C !uwD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a N_M
//Utility.log(in.readLine()); ,Y}HP3
sHeader=httpConnection.getHeaderFieldKey(i); .,feRK>3
if(sHeader!=null) &Tl3\T0D
{ ;B!&( 50e
if(sHeader.equals("Content-Length")) z+Y0Zh";/#
{ +AXui|mn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]BX|G`CCc
break; a^|mF# z
} 0urQA_JC
} fF<~2MiKw
else 4R}2H>VV%
break; z${DW@o3
} &(irri_
} J4=~.&6
catch(IOException e){e.printStackTrace ();} %~G)xK?W*
catch(Exception e){e.printStackTrace ();} Y+lZT4w
_?mu2!X
V\4'Hd
Utility.log(nFileLength); 'V } -0
3-z57f,}6~
o5A@U0c_
return nFileLength; b$%W<D
} l2z@t3{
$xNZ.|al
G4]T
//保存下载信息（文件指针位置） E ekX|*
private void write_nPos() 5_0Eh!sx
{ 51l:
try{ CO-9-sQx
output = new DataOutputStream(new FileOutputStream(tmpFile)); AvH^9zEE(
output.writeInt(nStartPos.length); qy/xJ>:
for(int i=0;i<nStartPos.length;i++) r m\]
{ UJ n3sZ<}
// output.writeLong(nPos); PkMN@JS
output.writeLong(fileSplitterFetch.nStartPos); XeJn,=
output.writeLong(fileSplitterFetch.nEndPos); K#tT \
} z'j4^Xz?%$
output.close(); Qne@Vf kA
} bRfac/:}
catch(IOException e){e.printStackTrace ();} o4\\q66K
catch(Exception e){e.printStackTrace ();} 9J$N5
} lE'2\kxI?
Wv8?G~>
KZ>cfv-&a
//读取保存的下载信息（文件指针位置） u{o3
private void read_nPos() RGf&KV/
{ RG0kOw0
try{ -LhO </l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J<yt/V]
int nCount = input.readInt(); o7;lR?
nStartPos = new long[nCount]; eD4X:^@
nEndPos = new long[nCount]; Uyj6Ij_Pj)
for(int i=0;i<nStartPos.length;i++) 58V`I5_
{ <Y:{>=
nStartPos = input.readLong(); Nu/wjx$b
nEndPos = input.readLong(); B/0Xqyu
} +Hgil
input.close(); f; w\k7 #
} C6Lc
catch(IOException e){e.printStackTrace ();} =;ClOy9
catch(Exception e){e.printStackTrace ();} i}[cq_wJ
} j4k\5~yzS
gF#HNv
Py y!B
private void processErrorCode(int nErrorCode) 3K!(/,`
{ S6Y2(qdP
System.err.println("Error Code : " + nErrorCode); |Bz1u|uc
} [;t-XC?[nk
-Aaim`06bv
0"}J!c<g
//停止文件下载 kOdXbw9v
public void siteStop() ~t^ Umx"Ew
{ 1o`zAJ8|2
bStop = true; 4A"3C
for(int i=0;i<nStartPos.length;i++) \2)D
fileSplitterFetch.splitterStop(); xsu9DzPf&{
:y'EIf
<-;/,uu
} ,cE yV74
} `,QcOkvbC
//负责部分文件的抓取 VK286[[fv
**FileSplitterFetch.java @QteC@k
*/ 0v+-yEkw
package NetFox; l0 =[MXM4
/s*.:cdH
e`n+U-)z
import java.io.*; R!f<6l8#W
import java.net.*; txE=AOY5
t.y-b`v
<yl%q*gls
public class FileSplitterFetch extends Thread { z_93j3#
O,6Wdw3+-3
~=va<%{ U
String sURL; //File URL ;NU-\<Q{
long nStartPos; //File Snippet Start Position VWq]w5oQO
long nEndPos; //File Snippet End Position '_d4[Olu
int nThreadID; //Thread's ID 5EU~T.4C<
boolean bDownOver = false; //Downing is over I+=+ ,iXhB
boolean bStop = false; //Stop identical wg%g(FO
FileAccessI fileAccessI = null; //File Access interface % IHIXncv[
"!+gA&
{ETM >
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z_Wzm!:
{ J3`0i@
this.sURL = sURL; :of(wZa3Q
this.nStartPos = nStart; Hz\@#
this.nEndPos = nEnd; |Dt_lQp#
nThreadID = id; (\0 <|pW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .G.WPVE
} CYRZ2Yrk?"
/~MH]Gh
4-~Z{#-
public void run() &rGB58
{ KL9k9|!p
while(nStartPos < nEndPos && !bStop) KL3Z(
{ ? D _kQl
>H^#!eaqw
e2f+Fv 9
try{ {`QA.he.
URL url = new URL(sURL); 8Qo'[+4;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6<EGH*GQ$
httpConnection.setRequestProperty("User-Agent","NetFox"); N_IKH)
String sProperty = "bytes="+nStartPos+"-"; Cb1w8l0
httpConnection.setRequestProperty("RANGE",sProperty); D"J',YN$
Utility.log(sProperty); g5 T
0z'GN#mT5
S=(<m%f
InputStream input = httpConnection.getInputStream(); Y=p!xr>
//logResponseHead(httpConnection); h);^4cU
M?!@L:b[
^|H={pd'c0
byte[] b = new byte[1024]; #l ZK_N|1x
int nRead; N+'j on}U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _Ao$)Gu)
{ P0e-v0
nStartPos += fileAccessI.write(b,0,nRead); U@M3.[jw
//if(nThreadID == 1) #~!"`B?#*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `J1HQ!Z
} E7t;p)x
7i*eKC`ZqK
;h\T7pwwb
Utility.log("Thread " + nThreadID + " is over!"); ;xZjt4M1
bDownOver = true; HcgvlFb
//nPos = fileAccessI.write (b,0,nRead); TjyL])$
} 8q@Z
catch(Exception e){e.printStackTrace ();} pZ&,YX
} yEq7ueJ'
} TG%B:^Yz!
;%9]G|*{
T1]?E]m{
//打印回应的头信息 7Ml4u%?
public void logResponseHead(HttpURLConnection con) h:nybLw?
{ |@vkQ
for(int i=1;;i++) CZ<T@k
{ gxN>q4z
String header=con.getHeaderFieldKey(i); L-T,[;bl
if(header!=null) DcW?L^Mst
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <.Ws; HN}
Utility.log(header+" : "+con.getHeaderField(header)); 1Y|a:){G
else j-":>}oW2.
break; ]1|P|Jp
} |'q%9#
} D7;9D*o\
$@D a|d4
g1s%x=7/
public void splitterStop() #;$]M4
{ xWxc1tT`
bStop = true; 93>4n\
} Qc; kj
x@t?7 o\&
z3Q&O$5\
} 2yZr!Rb~*
"f,{d}u
"2l`XH
/* @1MnJP
**FileAccess.java "9wD|wsz
*//文件访问(定位，写) p+;& Gg54
package NetFox; %{@Q7
import java.io.*; 98>GHl'lM
jN\u}!\O
Cf 2@x
public class FileAccessI implements Serializable{ i"WYcF|
*'?7OL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FJ:^pROpm
RandomAccessFile oSavedFile; 5~L]zE
long nPos; cCe~OlXQ
lN,?N{6s
j]Jgz<
public FileAccessI() throws IOException BAf$tyh
{ 8]ZzO(=@{
this("",0); .T| }rB<c
} 0zaK&]oY0
=dmr,WE
T5(S2^)o
public FileAccessI(String sName,long nPos) throws IOException iwotEl0*{
{ ,`@pi@<"#
oSavedFile = new RandomAccessFile(sName,"rw"); 7?$?Yu
this.nPos = nPos; LQ jbEYp
oSavedFile.seek(nPos); ={qcDgn~C
} eU[g@Pq:Y
o*S_"
\^x{NV@v42
public synchronized int write(byte[] b,int nStart,int nLen) $ik*!om5
{ P{TJ$
int n = -1; cHs3:F~~
try{ 8xAV[i
oSavedFile.write(b,nStart,nLen); Mo,&h?VOM?
n = nLen; U1[)eD`
} M:S-%aQ_<y
catch(IOException e) \N,ox(f?gW
{ 9)Fx;GxL
e.printStackTrace (); tt"<1 z@
} NRi5 Vp2=
c-a,__c?hx
2KlQ[z4Ir
return n; ?=VvFfv%
} (_T{Z>C/J
6':iW~iI
WYP;s7_
} ;<[X\;|'
+yGQt3U
,T$ts
/* qJhsMo2IH
**SiteInfoBean.java 1Kg0y71"
*/ f7Gn$E|/r;
package NetFox; d1b]+AG4
;cor\R
dzf2`@8#
public class SiteInfoBean { eqbN_$>
#9vC]Gm
Shm> r@C?
private String sSiteURL; //Site's URL /^.|m3
private String sFilePath; //Saved File's Path KZm&sk=QM-
private String sFileName; //Saved File's Name Gt w>R
private int nSplitter; //Count of Splited Downloading File $Ome]+0
c8l>OS5i3_
j4.wd RK
public SiteInfoBean() $v^hzC
{//nSplitter的缺省值为5 OQVrg2A%(
//default value of nSplitter is 5 %TB(E<p`
this("","","",5); I6>J.6luF9
} RK3yq$
$l7^-SK`E
64s;EC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AK:cDKBO
{ o[|[xuTm
sSiteURL= sURL; Y'v[2s
sFilePath = sPath; ]lB zpD
sFileName = sName; 5xQ-f
this.nSplitter = nSpiltter; >=~\b
2]>O ZhS
}3pM,.
} @<.@X*#I
Gw M:f/eV
(3#PKfY+
public String getSSiteURL() I \:WD"
{ &V"oJ}M/a
return sSiteURL; !X>u.}?g
} e+ xQ\LH
Sj9fq*
YOCEEh?
public void setSSiteURL(String value) $.G 7Vt
{ Dl,QCZeM
sSiteURL = value; x7j#@C
} *@U{[J
hHs/Qtq
#6`5-5Ks;
public String getSFilePath() P3M$&::D-
{ 6{Wo5O{!\
return sFilePath; f:c'j`
} 8|u4xf<
7Cgi&
aZfMeW
public void setSFilePath(String value) u v%Q5O4
{ bJ^JK
sFilePath = value; >ohH4:
} &w@]\7L,:
DaQ"Df_X
UKS5{"=T[
public String getSFileName() )uPJ? 2S9
{ S-Uod y
return sFileName; @"@a70WHk
} .3!Wr*o
IqOg{#sm
.sMs_ 5D
public void setSFileName(String value) s**<=M GK
{ 36d nS>4
sFileName = value; j\>LJai"
} .l}Ap7@
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_|k$[^ln^
public int getNSplitter() ZsmOn#`=^}
{ #&3,T1i`
return nSplitter; rpNb.
} .`or^`X3
[ks_wvY:'
y^.66BH
public void setNSplitter(int nCount) *}[\%u$ T
{ ;>6< u.N
nSplitter = nCount; K$E3RB_F
} b#j:)PA0C
} 2HbnE&
eUPa5{P
9&mSF0q
/* bO~y=Pa\
**Utility.java mHD_cgKN
*/ WT *"V<Z
package NetFox; `lhw*{3A
AGBV7Kk
exRw, Nk4
public class Utility { 7DB_Z/uU
,_z79tC{s
V<ESjK8
public Utility() XLh)$rZ
{ b)wcGBS
2u{~35
w)btv{*
} k"wQ9=HP7
:]3X Ez
//线程睡眠 Vl^(K_`(
public static void sleep(int nSecond) ~!S3J2kG{
{ Pt]>AW;i
try{ K<JzIuf&
Thread.sleep(nSecond); ts]e M1;
} FU`(mQ*Yd
catch(Exception e) *$p*'vR
{ hmy%X`%j
e.printStackTrace (); r )|3MUj
} r]B8\5|<d
} 2y[Q
=8FvkNr
//日志 W4$o\yA]
public static void log(String sMsg) (d9~z
{ ' jciX]g
System.err.println(sMsg); A40DbD\^ad
} >e]g T
(;NJ<x
''17(%
public static void log(int sMsg) woI5aee|
{ =H95?\}T[
System.err.println(sMsg); WtSs:D
} K#"=*p,
} ,p2UshOmd
Q*M#e
lg%fjBY
/* Vaxg
**TestMethod.java !-I,Dh-A
*/ DE13x*2
package NetFox; I8#2+$Be+@
e=amh
t}t(fJHY`
public class TestMethod { _~FfG!H ^X
aq,1'~8XR
xC76jE4
public TestMethod() 0TN28:hcD
{ ///xx/weblogic60b2_win.exe so))J`ca)
try{ nz 10/nw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R'c*CLaiE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W'G|sk
SiteFileFetch fileFetch = new SiteFileFetch(bean); d_[H|H9i6
fileFetch.start(); )\wkVAm
} PgtLyzc
catch(Exception e){e.printStackTrace ();} sG g458
Bwg(f_[1
79DNNj~
} ixTjXl2g
jCd]ENl+_
]3r}>/2(
public static void main(String[] args) Upz)iOqLi
{ y4\X~5kU
new TestMethod(); iSfRJ:_&6
} 44CZl{pt
} [8ZDMe
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