社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 8056阅读
  • 0回复

http断点续传简单实现(java)

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
/* _q 9lr8hx  
**SiteFileFetch.java ,,j=RG_  
*/ D/6@bcCSY  
package NetFox; S2GBX1  
import java.io.*; >wm$,%zk  
import java.net.*; u~T$F/]k>  
i3WmD@  
bOGDz|H``  
public class SiteFileFetch extends Thread { Ch!Q?4  
|+=:x]#vV  
3jdB8a]T_  
SiteInfoBean siteInfoBean = null; //文件信息Bean <cOE6;d#  
long[] nStartPos; //开始位置 uV:uXQni``  
long[] nEndPos; //结束位置 7[<sl35  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &,kB7r"  
long nFileLength; //文件长度 I;4CvoT  
boolean bFirst = true; //是否第一次取文件 }AfPBfgC1z  
boolean bStop = false; //停止标志 I; }%k;v6  
File tmpFile; //文件下载的临时信息 "RX5] eJc\  
DataOutputStream output; //输出到文件的输出流 iOXP\:mPo  
$u.T1v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) oK1[_ko|  
public SiteFileFetch(SiteInfoBean bean) throws IOException i|noYo_Ah\  
{ -&$%m)wN  
siteInfoBean = bean; R;,HtN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); K?m:.ZM  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); kb\v}gfiD/  
if(tmpFile.exists ()) |.8=gS5  
{ KKXb,/  
bFirst = false; |]3);^0  
read_nPos(); -6Si  
} j/ IZm)\  
else %~VIxY|d  
{ S_;:iC]B  
nStartPos = new long[bean.getNSplitter()]; pXlBKJmW  
nEndPos = new long[bean.getNSplitter()]; ` i^1U O  
} "J:NW_U  
\$|UFx  
~:b~f]lO  
nt`l6b  
} RSeezP6#  
qNVw+U;2P  
uvM8 8#  
public void run() `B 0*/ml  
{ >A "aOV>K  
//获得文件长度 &-Y:4.BXZ  
//分割文件 07Cuoqt2  
//实例FileSplitterFetch ul&7hHp_u%  
//启动FileSplitterFetch线程 P(+ar#,G  
//等待子线程返回 x=+I8Q4:  
try{ k<hO9;#qpL  
if(bFirst) I~6 ;9TlQ  
{ d>-EtWd  
nFileLength = getFileSize(); <aD+Ki6  
if(nFileLength == -1) `7n,(  
{ u"|nu!p`  
System.err.println("File Length is not known!"); gbZX'D  
} M8Lj*JN  
else if(nFileLength == -2) P[oB'  
{ CfnCi_=[`  
System.err.println("File is not access!"); ne*aC_)bT  
} sb5kexGxkc  
else PS]X Lz  
{ 2 g==98>cg  
for(int i=0;i<nStartPos.length;i++) 3yX^R^`  
{ <Y6>L};  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1vd+p!n  
} 7NqV*  
for(int i=0;i<nEndPos.length-1;i++) tqf-,BLh  
{ =#fvdj  
nEndPos = nStartPos[i+1]; tR/ JY;jn  
} TI&J>/z;$  
nEndPos[nEndPos.length-1] = nFileLength; e%>E| 9*u  
} rt;>pQ9,  
} 0zNS;wvv&  
4Lb<#e13R?  
U]3JCZ{]0E  
//启动子线程 u8=|{)yL  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (o=iX,@'2  
for(int i=0;i<nStartPos.length;i++) Q{kuB+s  
{ Nh-* Gt?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vi-@z;k  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |@|D''u>6  
nStartPos,nEndPos,i); 4B pm{b  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qm_E/B  
fileSplitterFetch.start(); <O&s 'A[  
} T^SOq:m&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M#|xj <p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _<Tz 1>j=  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rznr 9L  
nEndPos = " + nFileLength); vM8]fSc  
// fileSplitterFetch[nPos.length-1].start(); 5?"ZM'4  
|u=57II#xK  
XA%?35v~  
//等待子线程结束 !4fL|0  
//int count = 0; M-t9zT  
//是否结束while循环 D1a2|^zt  
boolean breakWhile = false; eU*h qy?0  
Y?x3JU0_  
k0|InP7  
while(!bStop) ^2tCDm5  
{ ]~,'[gWb  
write_nPos(); ;[ojwcK[ZF  
Utility.sleep(500); d1TG[i<J_  
breakWhile = true; (Zkt2[E`  
?y kIi/  
}wKU=Vm  
for(int i=0;i<nStartPos.length;i++) kY&j~R[C  
{ :l{-UkbB  
if(!fileSplitterFetch.bDownOver) 5j %jhby?  
{ E2cmT$6  
breakWhile = false; LdV_7)  
break; <jjaqDSmz  
} K;O\Pd  
} y6\#{   
if(breakWhile) qr1^i1%\  
break; V#Eq74ic  
aqgSr|  
[;+YO)  
//count++; EY(4 <;)  
//if(count>4) NKN!X/P  
// siteStop(); {fs(+ 0ei  
} eP8wTStC  
&40d J~SQ  
|/Z4lcI  
System.err.println("文件下载结束!"); 6|x<) Gc  
} PT=%]o]  
catch(Exception e){e.printStackTrace ();} NO)* UZ  
} ~-x\E#(  
$@X,J2&  
,;;~dfHm  
//获得文件长度 &kGSxYDk%  
public long getFileSize() XCY4[2*a>  
{ I;LqyzM  
int nFileLength = -1; H>?@nYP  
try{ 5sRNqTIr  
URL url = new URL(siteInfoBean.getSSiteURL()); L;;x%>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &0myA_So  
httpConnection.setRequestProperty("User-Agent","NetFox"); [aW#7  
-!" 8j"pA:  
B Xp3u|t  
int responseCode=httpConnection.getResponseCode(); J2-xnUa]7  
if(responseCode>=400) 6 AY%o nY  
{ L'(^[vR(  
processErrorCode(responseCode); 9dAsXEWh  
return -2; //-2 represent access is error mj pH)6aD0  
} ?Z"}RMM)8  
wlJ_, wA  
1Y_fX  
String sHeader; 2 q>4nN  
dpS  
%"tf`,d~3  
for(int i=1;;i++) gxiJ`. D=  
{ 2]l*{l^ Bl  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v%r!}s  
//Utility.log(in.readLine()); f/xBR"'  
sHeader=httpConnection.getHeaderFieldKey(i); IdM ;N  
if(sHeader!=null) \% (R~ H  
{ S<44{ oH  
if(sHeader.equals("Content-Length")) x<"e  
{ vv3?ewr y  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $k dfY'u  
break; FM5$83Q  
} Nz8iU@!a  
} [(1O_X(M  
else =0A{z#6  
break; M&L"yQA  
} |2 Dlw]d  
} "+Kr1nW  
catch(IOException e){e.printStackTrace ();} & b%6pVj  
catch(Exception e){e.printStackTrace ();} ,b/0_Q  
>2ct1_  
5:6mptn>  
Utility.log(nFileLength); QP'* )gjO7  
(NP=5lLH  
GIp?}tM  
return nFileLength; n D?XP<9UU  
} hd900LA}  
p"ZPv~("V  
d7 @ N~<n  
//保存下载信息(文件指针位置) PO #FtG  
private void write_nPos() D:f#  
{ HHdc[pJ0D  
try{ kG E|17I  
output = new DataOutputStream(new FileOutputStream(tmpFile)); h<uQ~CQg  
output.writeInt(nStartPos.length); R!`#pklB  
for(int i=0;i<nStartPos.length;i++) UV=TU=A\o  
{ ls=<c<  
// output.writeLong(nPos); 1i{B47|  
output.writeLong(fileSplitterFetch.nStartPos); &]5<^?3  
output.writeLong(fileSplitterFetch.nEndPos); Zhw _L  
} d(&vIjy  
output.close(); T]+*} C  
} Z]aSo07  
catch(IOException e){e.printStackTrace ();} YWTo]DJV  
catch(Exception e){e.printStackTrace ();} McfSB(59  
} m<j ^cU#J  
\.{?TB  
zMDR1/|D  
//读取保存的下载信息(文件指针位置) .UJk0%1  
private void read_nPos() "5@Y\L  
{ wM><DrQ  
try{ =w8*n2  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >k:)'*  
int nCount = input.readInt(); ,5q^/h  
nStartPos = new long[nCount]; t ;[Me0  
nEndPos = new long[nCount]; RD~QNj9,T  
for(int i=0;i<nStartPos.length;i++) z*FlZLHY  
{ Ih{~?(V$  
nStartPos = input.readLong(); T_r[#j  
nEndPos = input.readLong(); *rWE.4=&  
} ?Hy++  
input.close(); B]jh$@  
} r+>9O  
catch(IOException e){e.printStackTrace ();} 1~j.jv$  
catch(Exception e){e.printStackTrace ();} c$p1Sovw  
} thOCzGJ$  
p@P[pzxI  
X,~8 ) W  
private void processErrorCode(int nErrorCode) 4}gwMjU-B  
{ GU!|J71z  
System.err.println("Error Code : " + nErrorCode); am`eist:  
} J9 /w_,,R$  
"5{\0CfS  
4((Z8@iX/  
//停止文件下载 E_$ ST3  
public void siteStop() BWd?a6nU}  
{ ;DGp7f#9  
bStop = true; <F&S   
for(int i=0;i<nStartPos.length;i++) a"~W1|JC"  
fileSplitterFetch.splitterStop(); rq$%  
$UKDXQF"  
e&E*$G@.7  
} qWo|LpxWt  
} DD;PmIW  
//负责部分文件的抓取 "|f;   
**FileSplitterFetch.java m|p}Jf!  
*/ A=BpB}b  
package NetFox; T%Z`:mf  
~]N% {;F}  
2-2'c?%  
import java.io.*; ? [ =P  
import java.net.*; yp8 .\.  
cLamqZf3  
MECR0S9  
public class FileSplitterFetch extends Thread { aX0sy\Z]j  
^E>}A  
enZW2o97c  
String sURL; //File URL h4sEH  
long nStartPos; //File Snippet Start Position XxV]U{i!  
long nEndPos; //File Snippet End Position qbB.Z#w  
int nThreadID; //Thread's ID >GqIpfn  
boolean bDownOver = false; //Downing is over GJ!usv u  
boolean bStop = false; //Stop identical x< imMJ  
FileAccessI fileAccessI = null; //File Access interface  d+=;sJ  
i^j{l_-JE  
W&G DE  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 594$X@ !v  
{ \,~gA   
this.sURL = sURL; 0\u_ \%[  
this.nStartPos = nStart; ; <3w ,r  
this.nEndPos = nEnd; <;M6s~  
nThreadID = id; p_tMl%K  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P^+Og_$  
} *,mbZE=<  
\}Hk`n)Aq  
b@nbXm]Z  
public void run() H,] D}r  
{ ;b(/PH!O  
while(nStartPos < nEndPos && !bStop)  Zuwd(q  
{ BC&Et62*  
=w,%W^"E  
^1}}-9q  
try{ hX_;gR&R  
URL url = new URL(sURL); D4_D{\xhO  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +BmA4/P$  
httpConnection.setRequestProperty("User-Agent","NetFox"); df}B:?Ew.  
String sProperty = "bytes="+nStartPos+"-"; 4ajBMgD]KG  
httpConnection.setRequestProperty("RANGE",sProperty); -j<m0XUQ  
Utility.log(sProperty); m_oBV|v{  
852$Ui|I  
y=-d*E  
InputStream input = httpConnection.getInputStream(); ZO:{9vt=/  
//logResponseHead(httpConnection); >pz/wTOi  
-K+grsb g  
J>x)J}:;  
byte[] b = new byte[1024]; R0{+Xd  
int nRead; I C7n;n9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :x= ZvAvo  
{ r0?`t!% V  
nStartPos += fileAccessI.write(b,0,nRead); Xo }w$q5  
//if(nThreadID == 1)  ,8@@r7  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B-JgXW.\0  
} CfA F.H  
S =eP/  
w Xfy,W  
Utility.log("Thread " + nThreadID + " is over!"); >(*jL  
bDownOver = true; <Eq^r h  
//nPos = fileAccessI.write (b,0,nRead); rXvvJIbi  
} l0Y(9(M@  
catch(Exception e){e.printStackTrace ();} foaNB=,  
} (iH5F9WO  
} ^h=;]vxO  
 6 5qH  
v='7.A  
//打印回应的头信息 eRC@b^~  
public void logResponseHead(HttpURLConnection con) Z3"f7l6  
{ I x-FJF-  
for(int i=1;;i++) {U7j  
{ X2Y-TE T  
String header=con.getHeaderFieldKey(i); amgYr$)m  
if(header!=null) ^i#F+Q`1  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QfRt3\^`  
Utility.log(header+" : "+con.getHeaderField(header)); mLKwk6I  
else )";g*4R[  
break; j =[Td   
} g7#_a6  
} ,!PNfJA2  
dLG5yx\js  
%]RzC`NZ  
public void splitterStop() rQ. j$U  
{ O zY&^:>  
bStop = true; ytr~} M%  
} <dh7*M  
!)KX?i[Q  
2A {k>TjQ  
} Z6 (;~"Em  
(T!Q  
e>y"V; Mj  
/* bZ:w_z[3=  
**FileAccess.java ZN',=&;n'  
*//文件访问(定位,写) 5H`k$[3V  
package NetFox; ?ZE1>L7e  
import java.io.*; m>:3Ku  
(H0nO7Bk  
WZ;f3 "  
public class FileAccessI implements Serializable{ .u)Po;e`  
pgfI1`h  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q_qc_IcM y  
RandomAccessFile oSavedFile; mp%i(Y"vp  
long nPos; o1-Zh!*a*  
<JDkvpckx.  
Z3T:R"l;  
public FileAccessI() throws IOException OV Iu&6#  
{ p7Gs  
this("",0); 5(tOQ%AQ  
} IgQW 5E#  
Z_cTuu0'  
m?>$!B4jFB  
public FileAccessI(String sName,long nPos) throws IOException ES<"YF  
{ bY&s $Ry3"  
oSavedFile = new RandomAccessFile(sName,"rw"); #*1\h=bzmW  
this.nPos = nPos; 3Q Zw  
oSavedFile.seek(nPos); q?e97a  
} E;9SsA  
7YkxIzE  
b:Wl B[5  
public synchronized int write(byte[] b,int nStart,int nLen) rW&8#&  
{ >& \QLo[5  
int n = -1; G}AfCd4  
try{ ^+Ec}+ Q  
oSavedFile.write(b,nStart,nLen); e(,sFhR  
n = nLen; r8}GiP0|  
} RWz^ MV5K  
catch(IOException e) *GTCVxu  
{ v.c2(w/P  
e.printStackTrace (); }q)o LC  
} %7z  
J}nE,U2  
uJ{N?  
return n; V2V^*9(wu@  
} XW%!#S&;X  
Cj31'  
Y_xPr%%A  
} GadQ \>  
4-lEo{IIM  
d {T3  
/* 3QL'uk  
**SiteInfoBean.java PGOi#x  
*/ )CSb\  
package NetFox; Lg sQz(-  
}pTy mAN  
e{>X2UNW  
public class SiteInfoBean { Wx;:_F7'\  
Yq $(Ex  
5NZob<<  
private String sSiteURL; //Site's URL Wm7Dy7#l  
private String sFilePath; //Saved File's Path &w- QMj M>  
private String sFileName; //Saved File's Name uF+if`?  
private int nSplitter; //Count of Splited Downloading File )?:V5UO\  
dl6d!Nz*  
1ZOHyO  
public SiteInfoBean() |l 03,dOF  
{//nSplitter的缺省值为5 Q+U}    
//default value of nSplitter is 5 %mAgE\y25  
this("","","",5); ?*tb|AL(R  
} u0Fu_Rtr  
pBG(%3PpW  
`sAz1/N  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x%jJvwb^|  
{ _}vD?/$L  
sSiteURL= sURL; FQ*4?D,A  
sFilePath = sPath; 9P#E^;L  
sFileName = sName; |nk&ir6  
this.nSplitter = nSpiltter; W8'cAY  
qHt!)j9GKv  
A<C`JN}  
} :lcZ )6&S  
g PU|Gv5  
&s>HiL>f  
public String getSSiteURL() 1l"A7 V  
{ zC\ pd#  
return sSiteURL; pE[ul  
} Q?B5@J  
)F,H(LblH  
jV;&*4if  
public void setSSiteURL(String value) zZ3,e L  
{ <iajtq<Z  
sSiteURL = value; ek1YaE  
} q.`+d[Q2  
z)='MKrEt-  
Ix93/FAn  
public String getSFilePath() qrsPY d  
{ BQ2EDy=}6  
return sFilePath; <]r.wn=}M  
} cor?#  
x JQde 4  
}eXzs_  
public void setSFilePath(String value) =toqEm~  
{ j{?,nJdQ  
sFilePath = value; 2$. ubA  
} Xm8 1axyf  
q g?q|W  
kL 6f^MoL  
public String getSFileName() RMMx6L|-:  
{ a)$"   
return sFileName; ?%J{1+hY  
} -ve{O-;  
rhO ]4A  
AB'q!7NR  
public void setSFileName(String value) O4ciD 1  
{ qba<$  
sFileName = value; T]l_B2.  
} yd2v_  
3/RmJ `c{  
;aExEgTq  
public int getNSplitter() wXIsc;  
{ 6TvlK*<r=  
return nSplitter; e; 5 n.+m  
} M:z)uLDw  
aT$q1!U`j2  
@C{IgV  
public void setNSplitter(int nCount) X3vTyIsn  
{ D *RF._  
nSplitter = nCount; b*S :wfw  
} ER~m &JI  
} 4J Bm|Pf(  
>Ip>x!wi  
Qctm"g|  
/* {y0#(8-&  
**Utility.java p:U9#(v)  
*/ =PWh,lWS  
package NetFox; Z;M]^?  
/.l8Jb4  
O'{UAb+-  
public class Utility { R| [mp%Q  
Y [k%<f  
4vq,W_n.hQ  
public Utility() xwhH_[  
{ 2qLRcA=R  
SV}q8z\  
p(in.Xz  
} >H?l[*9  
9 =7),`$  
//线程睡眠 rT9<_<  
public static void sleep(int nSecond) uUu]JDdz  
{ ?W-J2tgss{  
try{ [0U!Y/?6lA  
Thread.sleep(nSecond); ;A7HEx  
} Ymkk"y.w  
catch(Exception e) - ?_aYJ  
{ xjB2?:/2  
e.printStackTrace (); [ &RZ&  
} ESp)%  
} /_ }xTP"9  
GzxtC  &  
//日志 [ R1S+i  
public static void log(String sMsg) -f IX6  
{ t"k6wv;Tq  
System.err.println(sMsg); Fn.wd`'0  
} F#>?i}  
ig:,:KN  
A ^@:Ps  
public static void log(int sMsg) nQ 2V  
{ k_?xi OSh  
System.err.println(sMsg); ikf!7-,  
} W8+Daw1Nr  
} ,=whwl "tA  
fYU/Jn#  
,Q!sns[T  
/* k0~mK7k  
**TestMethod.java &0Yv*,4]  
*/ U\'.rT[#  
package NetFox; NKf][!bi  
6KC.l}Y*  
a<9gD,]P  
public class TestMethod { | Z'NMJU  
HTiqErD2_  
|!:ImX@  
public TestMethod() tn!z^W  
{ ///xx/weblogic60b2_win.exe gBfYm  
try{ ZLw7-H6Fh  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f(~xdR))eh  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M7!>-P  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |:Gz9u+  
fileFetch.start(); Hf!o6 o  
} yk OJhd3  
catch(Exception e){e.printStackTrace ();} OEmz`JJ67  
J4 [7*v  
UUi@ U  
} GADbXp3  
\o3)\ e]o  
Nr)v!z~y   
public static void main(String[] args) ][3H6T!ckL  
{ pwAawm  
new TestMethod(); SQx%CcW9d  
} spter35b[  
} QSPneYD  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五