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)); ?4`f@=}'K
} $)YalZ
for(int i=0;i<nEndPos.length-1;i++) "xI70c{
{ '048Qykt;
nEndPos = nStartPos[i+1]; t6q7w
} tZXq<k9
nEndPos[nEndPos.length-1] = nFileLength; (Sv=R(_s
} ;W 3#q:
} O#_\@f#[
c9ye[81
gB_gjn\
//启动子线程 R@df~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uv|RpIve:
for(int i=0;i<nStartPos.length;i++) sB@9L L]&|
{ Nf5zQ@o_y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i}L*PCP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vg^yjP{sv
nStartPos,nEndPos,i); $6l^::U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N,bH@Q.Ci
fileSplitterFetch.start(); Hg~8Td**
} >qy$W4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j'uzjs[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]\1H=g%Ou
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lNLa:j
nEndPos = " + nFileLength); og?L 9
// fileSplitterFetch[nPos.length-1].start(); *b4W+E
Z!+n/ D-1
5_\1f|,
//等待子线程结束 1rIL[(r4
//int count = 0; GU0[K#%
//是否结束while循环 w-"tA`F4
boolean breakWhile = false; F05]6NVv
6Z@?W
l3Qt_I)L
while(!bStop) V.e30u5
{ dDbH+kqO
write_nPos(); **CGkL
Utility.sleep(500); 03n+kh
breakWhile = true; {^.q6,l
r,<p#4(>_
W5uC5C*,l
for(int i=0;i<nStartPos.length;i++) bXz*g`=;
{ _<6E>"*m
if(!fileSplitterFetch.bDownOver) `l'Ine11
{ *x/H
breakWhile = false; +ovT?CMo
break; R('\i/fy
} e>UU/Ks
} ~}_S]^br
if(breakWhile) Sa-" G`
break; F AQx8P
k?}y@$[)
l(pP*2
//count++; Obx!>mI^6
//if(count>4) @rv)J[7Y&
// siteStop(); q%/\
} 8]i7wq#=
v*kX?J#]5
g;7W%v5wqk
System.err.println("文件下载结束！"); U UhlKV|5
} D/ tCB-+
catch(Exception e){e.printStackTrace ();} G|I}x/X"Q7
} BZa`:ah~x
98maQQWD
Jz]OWb *
//获得文件长度 cK,&huk
public long getFileSize() t>2EZ{N+y
{ mT>RQ.
int nFileLength = -1; -;O"Y?ME
try{ $Ji;zR4,
URL url = new URL(siteInfoBean.getSSiteURL()); QuBA'4ht
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IC6'>2'=T
httpConnection.setRequestProperty("User-Agent","NetFox"); ;*{Ls#
SAU` u]E
NE><(02qW
int responseCode=httpConnection.getResponseCode(); ` Nv1sA#C
if(responseCode>=400) QBCEDv&j
{ kZ0z]Y
processErrorCode(responseCode); l15Z8hYhj
return -2; //-2 represent access is error VFK]{!C_
} Q yhu=_&
T5-Yqz
d/b\:[B@
String sHeader; `NQ;|!
,E8g~ZUY9
ey$H2zmo
for(int i=1;;i++) ^e]h\G
{ DB0?H+8t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gX`C76P!
//Utility.log(in.readLine()); {*"\68e
sHeader=httpConnection.getHeaderFieldKey(i); N"7BV
if(sHeader!=null) (_Th4'(@Y
{ M}`T-"qf
if(sHeader.equals("Content-Length")) %Q=rm!Syv
{ ]l"9B'XR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SB:z[kfz|
break; )K]<\Q[
} od^o9(.W^
} %"ehZd0r
else {5 3#Xd
break; vcZ"4%w
} Y=/;7T
} +.v+Opp,
catch(IOException e){e.printStackTrace ();} ($!g= 7
catch(Exception e){e.printStackTrace ();} ;)vs=DK:)
4O4}C#6(4
)"g @"LJ=
Utility.log(nFileLength); ?z3|^oU~d
U^Iq]L
Y2|c;1~5$
return nFileLength; sfp.>bMj
} 9Qq%Fw_
Icx)+Mq
aNgJm~K0P
//保存下载信息（文件指针位置） L?(m5u~b
private void write_nPos() wS [k}
{ 1i#U&
try{ M(:_(4~
output = new DataOutputStream(new FileOutputStream(tmpFile)); AgWG4C=
output.writeInt(nStartPos.length); t'DIKug&
for(int i=0;i<nStartPos.length;i++) }:\e"Bfv
{ F<O<=Ww
// output.writeLong(nPos); =%{E^z>1
output.writeLong(fileSplitterFetch.nStartPos); qxHsmGV
output.writeLong(fileSplitterFetch.nEndPos); -3SRGr
} ;I>77gi`]
output.close(); $gdGII&n
} 5N907XVu
catch(IOException e){e.printStackTrace ();} GPAz#0p
catch(Exception e){e.printStackTrace ();} ig'4DmNC
} ,UfB{BW
RPkOtRKL=w
^ lG^.
//读取保存的下载信息（文件指针位置） ze`qf%
private void read_nPos() scZ'/(b-E
{ Oe0dC9H
try{ <7oZV^nd *
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7mYBxE/
int nCount = input.readInt(); /?C6oj1
nStartPos = new long[nCount]; ~{D:vj4>
nEndPos = new long[nCount]; h)T-7b
for(int i=0;i<nStartPos.length;i++) F5<GGEQb
{ _p| KaT``
nStartPos = input.readLong(); '~76Y9mv
nEndPos = input.readLong(); TzrU |D?
} yjucR Fl
input.close(); NTSKmCvQG
} 9|hPl-. .W
catch(IOException e){e.printStackTrace ();} F:-6Htmj
catch(Exception e){e.printStackTrace ();} ;W!hl<``d*
} !Op18hP$
Q?Uk%t\hwc
#~[mn_C
private void processErrorCode(int nErrorCode) <PQ[N[SU
{ \JGRd8S[
System.err.println("Error Code : " + nErrorCode); p+R8Mo;I
} <$`udP@
pl.=u0 *
<~Tfi*^+
//停止文件下载 7@i2Mz/eV
public void siteStop() [oS.B\Vc
{ }u~r.=
bStop = true; y{\(|j
for(int i=0;i<nStartPos.length;i++) }{e7wqS$&,
fileSplitterFetch.splitterStop(); G$ Ii
\4&FW|mx
Gp))1b';
} ?[q.1O
} &?7+8n&+
//负责部分文件的抓取 :=%`\\
**FileSplitterFetch.java :aMp,DfM]P
*/ 0N3S@l#,\A
package NetFox; q\87<=9J
!_[^%7"S1
J""N:X!1
import java.io.*; q,eXH8 x
import java.net.*; (?zZvW8
lb`2a3W/
y8\4TjS1
public class FileSplitterFetch extends Thread { V~qlg1h
cx(b5Z
0)3*E)g{
String sURL; //File URL agW#"9]WM
long nStartPos; //File Snippet Start Position zf^F.wW
long nEndPos; //File Snippet End Position mH09* Z
int nThreadID; //Thread's ID %D}]Z=gp
boolean bDownOver = false; //Downing is over g,cl|]/\d
boolean bStop = false; //Stop identical h3:dO|Z
FileAccessI fileAccessI = null; //File Access interface |CjE}5Op>
'D;'Pr]
dKTUW<C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GGchNt
{ pxs`g&3yd
this.sURL = sURL; qbe9 CF'@_
this.nStartPos = nStart; r`(U3EgP
this.nEndPos = nEnd; 18U CZ;)>
nThreadID = id; GPnSdGLC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FzGla})
} nLjo3yvV..
h|Uy!?l
K-*q3oh G
public void run() [-Dl,P=
{ t Sf`
while(nStartPos < nEndPos && !bStop) hgi9%>oUB
{ c/E6}OWA
VR9C< tMSi
ua vv
try{ }nJG<rY
URL url = new URL(sURL); +EBoFeeIG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); onj:+zl
httpConnection.setRequestProperty("User-Agent","NetFox"); bbU{ />yW
String sProperty = "bytes="+nStartPos+"-"; ,, G6L{&Z
httpConnection.setRequestProperty("RANGE",sProperty); qZ7/d,w
Utility.log(sProperty); %L$P']%t@
29=L7
KI="O6 h
InputStream input = httpConnection.getInputStream(); f i3<
//logResponseHead(httpConnection); K r&HT,>B
i3} ^j?jA2
]gQ4qu5
byte[] b = new byte[1024]; 5:H9B
int nRead; *xOrt)D=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DHV#PLbN$
{ T9+ ?A l
nStartPos += fileAccessI.write(b,0,nRead); +}@HtjM
//if(nThreadID == 1) VJeN m3WNb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xFY;aK
} v+|N7
nUvxO `2
b%<i&YY#
Utility.log("Thread " + nThreadID + " is over!"); 7=ZB?@bU~
bDownOver = true; 43Yav+G(+
//nPos = fileAccessI.write (b,0,nRead); \ oIVE+L/P
} 81|Xg5g)b
catch(Exception e){e.printStackTrace ();} ]S~Z8T-[
} Dyj5a($9"{
} \5_7!.
rE bC_<
@M-+-6+
//打印回应的头信息 2|)3Ly9
public void logResponseHead(HttpURLConnection con) ~a5p_xP
{ ?Q]{d'g(sx
for(int i=1;;i++) j[h4F"`-
{ r^k:$wJbRK
String header=con.getHeaderFieldKey(i); 5Qik{cWxBq
if(header!=null) 6 /Apdn1[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rnVh ]xJ
Utility.log(header+" : "+con.getHeaderField(header)); \S@;>A<J
else T}X#I'Z
break; +M6qbIO
} 8eSIY17
} *Ki ],>_~
u9FXZK7
+]Y&las
public void splitterStop() +t R6[%
{ {7)D/WY5
bStop = true; OgfmyYMtc
} vb}; _/#?
sSi1;9^o
MX?K3=j @>
} ]iuM2]
xaWmwsym
P.RlozF5;
/* ":*PC[)W
**FileAccess.java ;jTP|q?|{
*//文件访问(定位，写) hp}J_/+4n
package NetFox; B8_w3;x
import java.io.*; 5[M?O4mi
Ak$ghb
'@M
public class FileAccessI implements Serializable{ >yn%.Uoh@
d9[*&[2J|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0!rU,74I=
RandomAccessFile oSavedFile; H'$g!Pg
long nPos; XGEAcN
!p1OBS|
Gv}*Tw$
public FileAccessI() throws IOException Pt?]JJxl-
{ RR><so%
this("",0); J56+eC(
} B3'qmi<
@xW)&d\'
,ORZtj
public FileAccessI(String sName,long nPos) throws IOException &2{h]V6
{ -L6 rXQV@j
oSavedFile = new RandomAccessFile(sName,"rw"); a4X J0Tm
this.nPos = nPos; LF0gy3
oSavedFile.seek(nPos); sD.bBz
} I-i)D
})Rmu."\
Roy0?6O
public synchronized int write(byte[] b,int nStart,int nLen) O k_I}X
{ EW$ Je
int n = -1; =8j;!7p
try{ pc5-'; n
oSavedFile.write(b,nStart,nLen); TdP_L/>|J
n = nLen; E)>~0jv
} +}X?+Epm
catch(IOException e) 0,(U_+n
{ -@G|i$!
e.printStackTrace (); ]6</{b
} V{fYMgv
BUv;BzyV
~-Rr[O=E
return n; V#|#% 8
} R)t"`'6|
@?{n`K7{`
f 5_n2
} L._I"g5 H9
Nm#VA.~
$g _h9L
/* AL}c-#GG
**SiteInfoBean.java ` &|Rs
*/ z?h\7 R
package NetFox; J}TS-j0
;k/y[ x}
^v3ytS
public class SiteInfoBean { 1^R@X
6!/e_a
h/`OG>./
private String sSiteURL; //Site's URL \*!?\Ko`W
private String sFilePath; //Saved File's Path @h([c
private String sFileName; //Saved File's Name }.4`zK&SB
private int nSplitter; //Count of Splited Downloading File KSuP'.l
FgNO#%
W{Ie(hf
public SiteInfoBean() 8^$}!9B~JZ
{//nSplitter的缺省值为5 ];^A8?
//default value of nSplitter is 5 RM-|?%
this("","","",5); NyJU?^f&v
} Wk'KN o
k _hiGg
18Pc4~>0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =XJ SE+ 7
{ Q0!gTV
sSiteURL= sURL; KB7CO:
sFilePath = sPath; 9<WMM)
sFileName = sName; f/?# 1
this.nSplitter = nSpiltter; 4 Yc9Ij
vd SV6p.d
4<70mUnt
} 5P -IZ8~$
U{RW=sYB~9
S,lJ&Rsu
public String getSSiteURL() 3otia;&B
{ #DwTm~V0"
return sSiteURL; cuBOE2vB.
} g[44YrRD
kG &.|
kW4/0PD
public void setSSiteURL(String value) X(?.*m@+TB
{ z6B/H2
sSiteURL = value; B1JdkL 3h
} utQE$0F
nE+sbfC
*pk*ijdB
public String getSFilePath() r{$ip"f
{ bAeC=?U
return sFilePath; yW^[{)V 3%
} _$NFeqLww
=ILs[p
V? w;YTg
public void setSFilePath(String value) 8uM>UpX
{ *.ri8
sFilePath = value; ]=2Ba<)m
} )(9>r/bq
?&_ -,\t
{^Vkxf]
public String getSFileName() BP,"vq$'+
{ V2,54YE
return sFileName; U voX\
} GX&BUP\
=_\5h=`Yx
n%"q>
public void setSFileName(String value) >:Na^+c
{ 4cRF3$amd
sFileName = value; $}jp=?,t
} `g<@F^x5
7u6o~(
Ha1E /b]K
public int getNSplitter() 84DneSpHsp
{ VtUe$ft
return nSplitter; Y _m4:9p
} ,u#uk7V
=GL}\I
cZk?o
public void setNSplitter(int nCount) 8E&}+DR?
{ o=_:g >5
nSplitter = nCount; T,@.RF
} Yewn
} cNtGjLpx;
[pUw(KV2m
;gYW!rM
/* NKvBNf|D
**Utility.java AV Gu*
*/ Yc3\NqQM
package NetFox; !jN}n)FSq
<|cnQj*
mM!'~{r[-
public class Utility { jGl8y!aM
)XmV3.rI
}&I\a
public Utility() ]>E*s3h
{ PUV)w\!&is
uMh[Ht^.
uz-,)
} +D[|L1{xb
'$YB -
//线程睡眠 +>/ariRr
public static void sleep(int nSecond) rdhK&5x*
{ onRxe\?D(
try{ t.$3?"60~
Thread.sleep(nSecond); H;s
} CnSfGsE>
catch(Exception e) hEi]-N\X
{ 'iA#lKG
e.printStackTrace (); ']Gqa$(YC
} k"&loh
} 'DO^($N
_ui03veA1
//日志 5XySF #
public static void log(String sMsg) `E+)e?z
{ U`N|pPe:w
System.err.println(sMsg); AD#]PSB
} V>ML-s9
:K>v F`SM
_BO:~x
public static void log(int sMsg) s:3 altv
{ dU1w)Y
System.err.println(sMsg); W^npzgDCo
} n|2`y?
} Z>gxECi
`bT!_Ru
Wt4ROj
/* Gdmh#pv
**TestMethod.java T6m#sVq
*/ (DJLq
package NetFox; :Rv?>I j
r8g4NsRVtv
;iR( Ir
public class TestMethod { tvXoF;Yq
I$/*Pt];
^]l^q'?>:
public TestMethod() PPk\W7G
{ ///xx/weblogic60b2_win.exe fZ1v|
try{ :f%FM&b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DX GClH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CF"$&+s9
SiteFileFetch fileFetch = new SiteFileFetch(bean); rCfr&>nn
fileFetch.start(); <6QG7i
} J!5BH2bg
catch(Exception e){e.printStackTrace ();} U/F<r3.`#
_OV\W'RrA
w}No ^.I*4
} ddvSi6
;,P-2\V/
arJ4^ d
public static void main(String[] args) :MeshzWK
{ D FDC'E
new TestMethod(); VH[r@Pn
} BCsz8U!
} MJNY#v3
点击下载更多相关资料